JAVA小白 程式設計練習題

JAVA小白 程式設計練習500題 超詳細!!!帶答案!!!持續更新中~

程式媛 泡泡 2021-05-09 21:46:11

73326

收藏 5583 分類專欄： 拓展補充 文章标簽： java 程式設計 練習題 筆試 基礎 版權聲明：本文為部落客原創文章，遵循 CC 4.0 BY-SA 版權協定，轉載請附上原文出處連結和本聲明。 本文連結： https://blog.csdn.net/weixin_43884234/article/details/116569562 版權

拓展補充 專欄收錄該内容 30 篇文章 87 訂閱 訂閱專欄

JAVA小白程式設計題練習

可能有很多剛入門的小白不知道自己如何能快速提升程式設計技巧與熟練度

其實大佬進階之路隻有一個~ 那就是瘋狂碼代碼!!!實踐出真知!!!

是以為了大家能夠想練習的時候有素材,泡泡給大家整理了一些練習題

由于平時比較忙,是以我在不定時努力更新中,歡迎監督~

500是立的Flag啊哈哈哈哈,我們共同努力吧,本帖已滿,以下為第二個練習帖的連結：

練習帖2 點我點我

希望能給大家帶來幫助~ 😃😃😃

文章目錄

• JAVA小白程式設計題練習
• • • [練習帖2 點我點我](https://chengxiaoyu-paopao.blog.csdn.net/article/details/118485298)
    • • • 希望能給大家帶來幫助~ :):):)
    • 練習題:通過代碼編寫，輸出一句話：“我要開始學習JAVA了，今天又是知識量滿滿的一天~”
    • 練習題：列印個人資訊案例，将一個人的一些個人資訊列印輸出
    • 練習題：拼接列印：輸出：XXX：這是我學習JAVA的第X年，我的期望薪資是XXX
    • 練習題：定義兩個整數，計算這兩個整數加減乘除運算的結果，并把結果列印到控制台
    • 練習題：預測身高案例：
    • 練習題：邏輯判斷
    • 練習題：最優選擇
    • 練習題: 接收使用者輸入的3個整數,并将它們的最大值作為結果輸出
    • 練習題: BMI 指數測試 BMI = 體重 (kg) / 身高² (m)
    • 練習題：最優選擇2
    • 練習題：求數字的絕對值
    • 練習題：求指定兩個數的最大公約數和最小公倍數
    • 練習題：銀行收入計算
    • 練習題：求稅後工資問題
    • 練習題: 手機選号:根據使用者輸入的手機号來确認使用者實際支付的價格
    • 練習題: 擷取郵箱名字
    • 練習題 : 分别通過for循環/While循環/do-While循環寫一個死循環
    • 練習題: 雞兔同籠問題(窮舉法)
    • 練習題:商品錄入系統
    • 練習題:求數字階乘(for循環版)
    • 練習題:多次生成随機數,并列印第一次出現大于0.999 時的次數與生成的随機數
    • 練習題:列印100以内除了尾數為3,5,7的所有數
    • 練習題:求質數:接收使用者輸入的數字,判斷是否為質數
    • 練習題:接收使用者輸入的數字,判斷在此範圍内質數的個數
    • 練習題:生成一個順序數組,将這個數組的元素打亂順序後輸出
    • 練習題:列印全三角形
    • 練習題：模拟雙色球生成案例
    • 練習題:求任意自然數各位數之和
    • 練習題:求任意數組中所有元素的最大值
    • 練習題:求1000以内的完數
    • 練習題： 随機數組的歸并問題
    • 練習題：周遊二維數組打油詩
    • 練習題:求猴子大王
    • 練習題:斐波那契問題
    • 練習題:古典問題：生兔兔問題
    • 練習題:列印水仙花數
    • 練習題：面向對象 封裝百分制分數
    • • • 分數類：
        • 測試類：
    • 練習題:面向對象 列印圖形
    • • • 形狀類【父類】：
        • 圓形類【子類】：
        • 方形類【子類】：
        • 直線類【子類】：
        • 測試類：随機生成圖形
    • 練習題:面向對象 設計士兵類
    • • • 士兵類：
        • 武器類：
        • 測試類1：
        • 測試類2：
    • 練習題:面向對象 設計寵物類
    • • • 寵物類【父類】：
        • 小貓類【子類】：
        • 小狗類【子類】：
        • 測試類：

練習題:通過代碼編寫，輸出一句話：“我要開始學習JAVA了，今天又是知識量滿滿的一天~”

public class TestPrint {

public static void main(String[] args) {

System.out.println(“我要開始學習JAVA了，今天又是知識量滿滿的一天~”);

}

}

• 1
• 2
• 3
• 4
• 5
• 6
• 7

練習題：列印個人資訊案例，将一個人的一些個人資訊列印輸出

public class TestPrint2 {

public static void main(String[] args) {

System.out.println(“海綿寶寶”);//字元串類型，我是海綿寶寶

System.out.println(3);//整數類型，今年3歲了

System.out.println(“海底”);//字元串類型，我的家在海底

System.out.println(true);//布爾類型，吃飯了嗎？吃啦，吃的蟹黃堡

System.out.println(10.99);//浮點類型，今天還收到了10.99的紅包

}

}

• 1
• 2
• 3
• 4
• 5
• 6
• 7
• 8
• 9
• 10
• 11

練習題：拼接列印：輸出：XXX：這是我學習JAVA的第X年，我的期望薪資是XXX

public class TestPrint3 {

public static void main(String[] args) {

//1.定義變量儲存姓名

String name = “派大星”;

//2.定義變量儲存年份

int year = 1;

//3.定義變量儲存期望薪資

double salary = 10000.0;

//4.拼接列印目标結果

System.out.println(name+"：這是我學習JAVA的第"+year+“年，我的期望薪資是”+salary);

}

}

• 1
• 2
• 3
• 4
• 5
• 6
• 7
• 8
• 9
• 10
• 11
• 12
• 13
• 14

練習題：定義兩個整數，計算這兩個整數加減乘除運算的結果，并把結果列印到控制台

public class TestPrint4 {

public static void main(String[] args) {

//1.定義變量儲存要計算的第一個數

int number1 = 1;

//2.定義變量儲存要計算的第二個數

int number2 = 2;

//3.列印輸出這兩個數計算的結果

System.out.println(number1+number2);

}

}

• 1
• 2
• 3
• 4
• 5
• 6
• 7
• 8
• 9
• 10
• 11
• 12

練習題：預測身高案例：

其實我們可以通過父母的身高大緻推斷出子女的身高，假定父母與子女的身高遺傳關系如下：

​ 兒子身高（厘米）＝(父親身高＋母親身高) ×1.08÷2

​ 女兒身高（厘米）＝(父親身高×0.923＋母親身高) ÷2

那已知：現有父親身高175CM,母親身高160CM。

請将預測的子女身高列印輸出

public class TestPrint5 {

public static void main(String[] args) {

//1.定義變量儲存父親的身高

double fatherHeight = 175;

//2.定義變量儲存母親的身高

double motherHeight = 160;

//3.計算兒子身高

double sonHeight = (fatherHeight + motherHeight) 1.08 / 2;

//4.計算女兒身高

double daughterHeight = (fatherHeight 0.923 + motherHeight) / 2;

//5.列印輸出最終計算的結果

System.out.println(“兒子預計身高” + sonHeight + “厘米”);

System.out.println(“女兒預計身高” + daughterHeight + “厘米”);

}

}

• 1
• 2
• 3
• 4
• 5
• 6
• 7
• 8
• 9
• 10
• 11
• 12
• 13
• 14
• 15
• 16
• 17

練習題：邏輯判斷

已知小紅同學有25元，她攢了幾天錢之後發現自己的現在的錢比原來的2倍還多出10塊。而小藍同學有30元，他攢了幾天錢之後發現自己的錢正好是原來的2倍。于是小胖說：小紅和小藍現在的錢一樣多，請問，他說的對嗎？

public class TestPrint4 {

public static void main(String[] args) {

//1.定義變量儲存小紅原來的錢數

int red = 25;

//2.定義變量儲存小藍原來的錢數

int blue = 30;

//3.求小紅同學現在的錢數

red = red 2 + 10;

//4.求小藍同學現在的錢數

blue = 2; //這是一種簡寫形式，等同于blue = blue *2;

//5.判斷并輸出兩個人的錢是否相等

System.out.println(red == blue);

}

}

• 1
• 2
• 3
• 4
• 5
• 6
• 7
• 8
• 9
• 10
• 11
• 12
• 13
• 14
• 15
• 16

練習題：最優選擇

某小夥想定一份外賣，商家的優惠方式如下：魚香肉絲單點24元，油炸花生米單點8元，米飯單點3元。訂單滿30元8折優惠。魚香肉絲優惠價16元，但是優惠價和折扣不能同時使用。那麼這個小夥要點這三樣東西，最少要花多少錢？

public class Demo3 {
    public static void main(String[] args) {
        //1.求不使用優惠時的總價
        double money1 = 24 + 8 + 3;
        //2.判斷折後總價
        money1 = (money1 <= 30 ? money1 : money1 * 0.8);
        //3.求使用優惠時的總價
        double money2 = 16 + 8 + 3;
        //4.判斷兩種花費哪個更少
        double money = money1 < money2 ? money1 : money2;
        //5.列印最終花費
        System.out.println(money);
    }
}
           

• 1
• 2
• 3
• 4
• 5
• 6
• 7
• 8
• 9
• 10
• 11
• 12
• 13
• 14

練習題: 接收使用者輸入的3個整數,并将它們的最大值作為結果輸出

import java.util.Scanner;

public class GetMaxNumber {

public static void main(String[] args) {

//1.提示并接收使用者輸入的三個整數,并交由變量a b c來儲存

System.out.println(“請輸入第一個整數:”);

int a = new Scanner(System.in).nextInt();

System.out.println(“請輸入第二個整數:”);

int b = new Scanner(System.in).nextInt();

System.out.println(“請輸入第三個整數:”);

int c = new Scanner(System.in).nextInt();

<span class="token comment">//2.對接收到的三個值進行比較</span>
    <span class="token comment">/**三元運算符 1 ? 2 : 3
     * 如果1号位置的表達式結果為true,結果就取2号位置的值,反之,就取3号位置的值*/</span>
    <span class="token comment">//2.1定義變量max來儲存a和b中的最大值</span>
    <span class="token keyword">int</span> max <span class="token operator">=</span> a<span class="token operator">&gt;</span>b <span class="token operator">?</span> a <span class="token operator">:</span> b<span class="token punctuation">;</span>
    <span class="token comment">//2.2比較max與c誰最大,并将最大值交由max來儲存</span>
    max <span class="token operator">=</span> max<span class="token operator">&gt;</span>c <span class="token operator">?</span> max <span class="token operator">:</span> c<span class="token punctuation">;</span>
    <span class="token comment">/**解決方案二:*/</span>
    <span class="token comment">//int max = a&gt;b?(a&gt;c?a:c):(b&gt;c?b:c);</span>
    <span class="token comment">//3.輸出結果</span>
    <span class="token class-name">System</span><span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span><span class="token string">"三個數的最大值是:"</span><span class="token operator">+</span>max<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>
           

}

• 1
• 2
• 3
• 4
• 5
• 6
• 7
• 8
• 9
• 10
• 11
• 12
• 13
• 14
• 15
• 16
• 17
• 18
• 19
• 20
• 21
• 22
• 23
• 24
• 25
• 26
• 27

練習題: BMI 指數測試 BMI = 體重 (kg) / 身高² (m)

接收使用者輸入的身高和體重,将判斷結果輸出

過輕：低于18.5

正常：18.5 ~ 22.9

偏胖：23 ~ 24.9

肥胖：25 ~ 29.9

重度肥胖：高于30

極度肥胖：高于40

import java.util.Scanner;

public class TestBMI {

public static void main(String[] args) {

//1.提示并接收使用者輸入的身高與體重資訊

System.out.print(“請輸入您的身高(機關為m)：”);

double height = new Scanner(System.in).nextDouble();

System.out.print(“請輸入您的體重(機關為kg)：”);

double weight = new Scanner(System.in).nextDouble();

<span class="token comment">//2.調用getBMI()方法，根據身高和體重資訊,輸出結果</span>
    <span class="token function">getBMI</span><span class="token punctuation">(</span>height<span class="token punctuation">,</span> weight<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>

<span class="token keyword">public</span> <span class="token keyword">static</span> <span class="token keyword">void</span> <span class="token function">getBMI</span><span class="token punctuation">(</span><span class="token keyword">double</span> h<span class="token punctuation">,</span> <span class="token keyword">double</span> w<span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
    <span class="token comment">//求出BMI指數</span>
    <span class="token keyword">double</span> bmi <span class="token operator">=</span> w <span class="token operator">/</span> <span class="token punctuation">(</span>h <span class="token operator">*</span> h<span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token comment">//定義一個變量r來儲存最終結果</span>
    <span class="token class-name">String</span> r <span class="token operator">=</span> <span class="token string">""</span><span class="token punctuation">;</span>

    <span class="token comment">//根據 bmi 指數範圍，來給r重新指派</span>
    <span class="token keyword">if</span> <span class="token punctuation">(</span>bmi <span class="token operator">&lt;</span> <span class="token number">18.5</span><span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
        r <span class="token operator">=</span> <span class="token string">"過輕"</span><span class="token punctuation">;</span>
    <span class="token punctuation">}</span> <span class="token keyword">else</span> <span class="token keyword">if</span> <span class="token punctuation">(</span>bmi <span class="token operator">&lt;=</span> <span class="token number">22.9</span><span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
        r <span class="token operator">=</span> <span class="token string">"正常"</span><span class="token punctuation">;</span>
    <span class="token punctuation">}</span> <span class="token keyword">else</span> <span class="token keyword">if</span> <span class="token punctuation">(</span>bmi <span class="token operator">&lt;=</span> <span class="token number">24.9</span><span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
        r <span class="token operator">=</span> <span class="token string">"偏胖"</span><span class="token punctuation">;</span>
    <span class="token punctuation">}</span> <span class="token keyword">else</span> <span class="token keyword">if</span> <span class="token punctuation">(</span>bmi <span class="token operator">&lt;=</span> <span class="token number">29.9</span><span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
        r <span class="token operator">=</span> <span class="token string">"肥胖"</span><span class="token punctuation">;</span>
    <span class="token punctuation">}</span> <span class="token keyword">else</span> <span class="token keyword">if</span> <span class="token punctuation">(</span>bmi <span class="token operator">&lt;=</span> <span class="token number">40</span><span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
        r <span class="token operator">=</span> <span class="token string">"重度肥胖"</span><span class="token punctuation">;</span>
    <span class="token punctuation">}</span> <span class="token keyword">else</span> <span class="token punctuation">{<!-- --></span>
        r <span class="token operator">=</span> <span class="token string">"極度肥胖"</span><span class="token punctuation">;</span>
    <span class="token punctuation">}</span>
    <span class="token comment">//列印最終結果</span>
    <span class="token class-name">System</span><span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span><span class="token string">"您的BMI指數："</span> <span class="token operator">+</span> bmi<span class="token punctuation">)</span><span class="token punctuation">;</span>

    <span class="token class-name">System</span><span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span><span class="token string">"您的體重屬于："</span> <span class="token operator">+</span> r<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>
           

}

• 1
• 2
• 3
• 4
• 5
• 6
• 7
• 8
• 9
• 10
• 11
• 12
• 13
• 14
• 15
• 16
• 17
• 18
• 19
• 20
• 21
• 22
• 23
• 24
• 25
• 26
• 27
• 28
• 29
• 30
• 31
• 32
• 33
• 34
• 35
• 36
• 37
• 38
• 39
• 40
• 41
• 42

練習題：最優選擇2

小藍同學想買一個價值8888元的新手機，她的舊手機在二手市場能賣1880元，而手機專賣店推出以舊換新的優惠，把她的舊手機交給店家，新手機就能夠打7.5折優惠。為了更省錢，小藍要不要以舊換新？

public class TestChoice {
    public static void main(String[] args) {
        //1.計算不使用以舊換新的花費
        int plan1 = 8888 - 1880;
        //2.計算以舊換新的花費
        double plan2 = 8888 * 0.75;
        //3.判斷兩種方式
        if(plan1 > plan2){
            System.out.println("使用以舊換新更省錢");
        }else{
            System.out.println("不使用以舊換新更省錢");
        }
    }
}
           

• 1
• 2
• 3
• 4
• 5
• 6
• 7
• 8
• 9
• 10
• 11
• 12
• 13
• 14

練習題：求數字的絕對值

絕對值是指一個數在數軸上所對應點到原點的距離，用“| |”來表示。負數的絕對值是他去掉負号以後的值，而非負數（0和正數）的絕對值是他本身。請定義一個方法，接收使用者輸入的數字，輸出絕對值結果。

import java.util.Scanner;

public class TestNum {

public static void main(String[] args) {

//1.接收使用者輸入的要測試的數字

System.out.println(“請輸入你要判斷的數字：”);

double input = new Scanner(System.in).nextDouble();

//2.調用求絕對值的方法并拿到方法執行後的結果（傳回值）

double result = getAbsNum(input);

//3.列印求出的結果

System.out.println(input+“的絕對值是：”+result);

}

<span class="token keyword">private</span> <span class="token keyword">static</span> <span class="token keyword">double</span> <span class="token function">getAbsNum</span><span class="token punctuation">(</span><span class="token keyword">double</span> input<span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
    <span class="token keyword">if</span><span class="token punctuation">(</span>input <span class="token operator">&gt;=</span><span class="token number">0</span><span class="token punctuation">)</span><span class="token punctuation">{<!-- --></span><span class="token comment">//如果是非負數</span>
        <span class="token keyword">return</span> input<span class="token punctuation">;</span><span class="token comment">//傳回本身的值</span>
    <span class="token punctuation">}</span><span class="token keyword">else</span><span class="token punctuation">{<!-- --></span><span class="token comment">//如果是負數</span>
        <span class="token keyword">return</span> <span class="token operator">-</span>input<span class="token punctuation">;</span><span class="token comment">//則值取反</span>
    <span class="token punctuation">}</span>
<span class="token punctuation">}</span>
           

}

• 1
• 2
• 3
• 4
• 5
• 6
• 7
• 8
• 9
• 10
• 11
• 12
• 13
• 14
• 15
• 16
• 17
• 18
• 19
• 20
• 21
• 22
• 23
• 24

練習題：求指定兩個數的最大公約數和最小公倍數

import java.util.Scanner;

public class NumTest {

public static void main(String[] args) {

System.out.println(“輸入兩個整數：”);

int a = new Scanner(System.in).nextInt();

int b = new Scanner(System.in).nextInt();

<span class="token keyword">int</span> d <span class="token operator">=</span> <span class="token function">zdgys</span><span class="token punctuation">(</span>a<span class="token punctuation">,</span>b<span class="token punctuation">)</span><span class="token punctuation">;</span><span class="token comment">//調用求最大公約數的方法</span>
  <span class="token keyword">long</span> x <span class="token operator">=</span> <span class="token function">zxgbs</span><span class="token punctuation">(</span>a<span class="token punctuation">,</span>b<span class="token punctuation">)</span><span class="token punctuation">;</span><span class="token comment">//調用求最小公倍數的方法</span>
  <span class="token class-name">System</span><span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span><span class="token string">"最大公約數："</span><span class="token operator">+</span>d<span class="token punctuation">)</span><span class="token punctuation">;</span>
  <span class="token class-name">System</span><span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span><span class="token string">"最小公倍數："</span><span class="token operator">+</span>x<span class="token punctuation">)</span><span class="token punctuation">;</span>
           

}

private static int zdgys(int a, int b) {

int min = a<b ? a : b;

for(int i=min; i>=1; i–) {

//i能把a和b同時整除

if(a%i0 && b%i0) {

return i;

}

}

//這句代碼根本不會執行，

//讓編譯可以通過

return 0;

}

private static long zxgbs(int a, int b) {

int max = a>b? a : b;

for(long i=max; ;i+=max) {

//i能同時被a和b整除

if(i%a0 && i%b0) {

return i;

}

}

}

}

• 1
• 2
• 3
• 4
• 5
• 6
• 7
• 8
• 9
• 10
• 11
• 12
• 13
• 14
• 15
• 16
• 17
• 18
• 19
• 20
• 21
• 22
• 23
• 24
• 25
• 26
• 27
• 28
• 29
• 30
• 31
• 32
• 33
• 34
• 35
• 36
• 37
• 38
• 39
• 40

練習題：銀行收入計算

某銀行推出了整存整取定期儲蓄業務，其存期分為一年、兩年、三年、五年，到期憑存單支取本息。存款年利率表如下：

​ 存期 年利率（%）

​ 一年 2.25

​ 兩年 2.7

​ 三年 3.25

​ 五年 3.6

請存入一定金額（1000起存），存一定年限（四選一），計算到期後得到的本息總額。

提示：

​ 存入金額和存入年限均由鍵盤錄入

​ 本息計算方式：本金+本金×年利率×年限

import java.util.Scanner;
public class BankDemo {
    public static void main(String[] args) {
        //1.提示并接收使用者輸入的存款金額
        System.out.println("請輸入存款金額：");
        int money = new Scanner(System.in).nextInt();
        //2.提示并接收使用者輸入的存款年限
        System.out.println("請輸入存款年限：");
        int year = new Scanner(System.in).nextInt();
        //3.定義變量用來儲存本金和利息之和
        double outMoney = 0;
        //4.根據利率和年限計算本息和
        if (year == 1) {
            outMoney = money + money * 2.25 / 100 * 1;
        } else if (year == 2) {
            outMoney = money + money * 2.7 / 100 * 2;
        } else if (year == 3) {
            outMoney = money + money * 3.25 / 100 * 3;
        } else if (year == 5) {
            outMoney = money + money * 3.6 / 100 * 5;
        } else {
            System.out.println("輸入的年限有誤");
        }
        //5.列印輸出
        System.out.println("存款" + year + "年後的本息是：" + outMoney);
    }
}
           

• 1
• 2
• 3
• 4
• 5
• 6
• 7
• 8
• 9
• 10
• 11
• 12
• 13
• 14
• 15
• 16
• 17
• 18
• 19
• 20
• 21
• 22
• 23
• 24
• 25
• 26
• 27

練習題：求稅後工資問題

2019年1月1日起，國家推出新的個人所得稅政策，起征點上調值5000元。也就是說稅前工資扣除三險一金（三險一金數額假設是稅前工資的10%）後如果不足5000元，則不交稅。如果大于5000元，那麼大于5000元的部分按梯度交稅，具體梯度比例如下：

​ 0 ~ 3000元的部分，交稅3%

​ 3000 ~ 12000元的部分，交稅10%

​ 12000 ~ 25000的部分 ， 交稅20%

​ 25000 ~ 35000的部分，交稅25%

​ 35000 ~ 55000的部分，交稅30%

​ 55000 ~ 80000的部分，交稅35%

​ 超過80000的部分，交稅45%

比如：小藍入職一家企業後，稅前工資是18000，則他每月該交個稅的部分是18000-1800-5000=11200元，個稅繳納數額是3000×3%+8200×10%=910元。稅後工資15290元。

請完成一個個稅計算程式，在使用者輸入稅前工資後，計算出他對應的納稅數額，以及稅後工資為多少？

import java.util.Scanner;
public class Demo5 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.println("請輸入您的稅前工資：");
        //2.鍵盤錄入稅前工資
        int money = sc.nextInt();
        //3.計算應納稅部分的工資
        double before = money - (money*0.1) - 5000;
        //4.定義個稅變量
        double shui = 0;
        //5.按照梯度範圍計算個稅數值
        if(before > 0 && before <=3000){
            shui = before * 0.03;
        }else if(before > 3000 && before <=12000){
            shui = 3000*0.03 + (before-3000) * 0.1;
        }else if(before > 12000 && before <=25000){
            shui = 3000*0.03 + 9000*0.1 +  (before-12000)*0.2;
        }else if(before > 25000 && before <=35000){
            shui = 3000*0.03 + 9000*0.1 + 13000*0.2 + (before-25000)*0.25;
        }else if(before > 35000 && before <=55000){
            shui = 3000*0.03 + 9000*0.1 + 13000*0.2 + 10000*0.25 + (before-35000)*0.3;
        }else if(before > 55000 && before <=80000){
            shui = 3000*0.03 + 9000*0.1 + 13000*0.2 + 10000*0.25 + 20000*0.3 + (before-55000)*0.35;
        }else if(before > 80000){
            shui = 3000*0.03 + 9000*0.1 + 13000*0.2 + 10000*0.25 + 20000*0.3 + 25000*0.35 + (before-80000)*0.45;
        }
        //6.計算稅後工資
        double after = money - (money*0.1) - shui;
        //7.列印個稅和稅後工資
        System.out.println("個人所得稅" + shui + "元");
        System.out.println("稅後工資" + after + "元");
    }
}
           

• 1
• 2
• 3
• 4
• 5
• 6
• 7
• 8
• 9
• 10
• 11
• 12
• 13
• 14
• 15
• 16
• 17
• 18
• 19
• 20
• 21
• 22
• 23
• 24
• 25
• 26
• 27
• 28
• 29
• 30
• 31
• 32
• 33
• 34

練習題: 手機選号:根據使用者輸入的手機号來确認使用者實際支付的價格

如果尾數為8，需支付辦卡費50元

如果尾數為4，需支付辦卡費用0元

如果是其他尾号,需支付辦卡費用20元

import java.util.Scanner;

public class PayCard {

public static void main(String[] args) {

//1.提示并接收使用者輸入的手機号

System.out.println(“請輸入您預選的手機号：”);

String tel = new Scanner(System.in).nextLine();//注意String類型資料一般用nextLine()

<span class="token comment">//2.調用getPrice()方法，來計算價格,注意需要把手機号tel作為參數傳入方法中</span>
    <span class="token function">getPrice</span><span class="token punctuation">(</span>tel<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>

<span class="token comment">//3.建立getPrice()</span>
<span class="token keyword">public</span> <span class="token keyword">static</span> <span class="token keyword">void</span> <span class="token function">getPrice</span><span class="token punctuation">(</span><span class="token class-name">String</span> tel<span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
    <span class="token comment">//3.1 手機号tel的長度，必須是11位的正确手機号--提前校驗,提高程式健壯性</span>
    <span class="token keyword">if</span><span class="token punctuation">(</span>tel<span class="token punctuation">.</span><span class="token function">length</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token operator">!=</span> <span class="token number">11</span><span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
        <span class="token class-name">System</span><span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span><span class="token string">"号碼格式錯誤"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
        <span class="token keyword">return</span><span class="token punctuation">;</span><span class="token comment">//結束方法，傳回到調用位置再繼續執行</span>
    <span class="token punctuation">}</span>

    <span class="token comment">/*比如我們拿到的手機号是tel="2313123123",想要拿到尾數,也就是最後一個字元
     * 需要用到 char c = tel.charAt(10)
     * 注意:由于下标也是從0開始,是以取第11個字元，它的下标位置是10
     */</span>
    <span class="token comment">//3.2擷取手機号的尾數</span>
    <span class="token keyword">char</span> c <span class="token operator">=</span> tel<span class="token punctuation">.</span><span class="token function">charAt</span><span class="token punctuation">(</span><span class="token number">10</span><span class="token punctuation">)</span><span class="token punctuation">;</span>

    <span class="token comment">//3.2定義用來儲存最終結果的變量price,初始值為0</span>
    <span class="token keyword">int</span> price <span class="token operator">=</span> <span class="token number">0</span><span class="token punctuation">;</span>

    <span class="token comment">//3.3根據c字元的值，來為price重新指派</span>
    <span class="token keyword">switch</span><span class="token punctuation">(</span>c<span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
        <span class="token keyword">case</span> <span class="token string">'8'</span><span class="token operator">:</span> price<span class="token operator">=</span><span class="token number">50</span><span class="token punctuation">;</span> <span class="token keyword">break</span><span class="token punctuation">;</span><span class="token comment">//尾數為8支付50</span>
        <span class="token keyword">case</span> <span class="token string">'4'</span><span class="token operator">:</span> price<span class="token operator">=</span><span class="token number">0</span><span class="token punctuation">;</span> <span class="token keyword">break</span><span class="token punctuation">;</span><span class="token comment">//尾數為4免費</span>
        <span class="token keyword">default</span><span class="token operator">:</span> price<span class="token operator">=</span><span class="token number">20</span><span class="token punctuation">;</span><span class="token comment">//其他情況需支付20</span>
    <span class="token punctuation">}</span>
    <span class="token comment">//3.4顯示結果</span>
    <span class="token class-name">System</span><span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span><span class="token string">"您實際應支付的價格為："</span><span class="token operator">+</span>price<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>
           

}

• 1
• 2
• 3
• 4
• 5
• 6
• 7
• 8
• 9
• 10
• 11
• 12
• 13
• 14
• 15
• 16
• 17
• 18
• 19
• 20
• 21
• 22
• 23
• 24
• 25
• 26
• 27
• 28
• 29
• 30
• 31
• 32
• 33
• 34
• 35
• 36
• 37
• 38
• 39
• 40
• 41
• 42

練習題: 擷取郵箱名字

接收使用者輸入的郵箱名，擷取郵箱的名字

比如：[email protected],輸出cxy

import java.util.Scanner;

public class GetEmailName {

public static void main(String[] args) {

System.out.println(“輸入email:”);

String e = new Scanner(System.in).nextLine();

//email位址e，傳遞到該方法，

//并得到方法傳回的名字，儲存到變量n

String n = getName(e);

System.out.println(n);

}

<span class="token keyword">static</span> <span class="token class-name">String</span> <span class="token function">getName</span><span class="token punctuation">(</span><span class="token class-name">String</span> email<span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
	<span class="token comment">/*
	 * "[email protected]"
	 *         |
	 *         index
	 *
	 * 1. 定位 "@" 的下标位置 index
	 * 2. 截取 [0, index)，直接傳回
	 * email.indexOf("@")
	 *        查找指定子串的位置
	 *        找不到，得到特殊值 -1
	 * email.substring(0, index)
	 *        截取 [0, index)
	 */</span>
	<span class="token comment">//找@的位置</span>
	<span class="token keyword">int</span> index <span class="token operator">=</span> email<span class="token punctuation">.</span><span class="token function">indexOf</span><span class="token punctuation">(</span><span class="token string">"@"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token keyword">if</span><span class="token punctuation">(</span>index <span class="token operator">==</span> <span class="token operator">-</span><span class="token number">1</span><span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span><span class="token comment">//找不到</span>
		<span class="token keyword">return</span> <span class="token string">"郵箱格式錯誤"</span><span class="token punctuation">;</span>
	<span class="token punctuation">}</span>
	<span class="token comment">//截取，直接傳回截取的結果</span>
	<span class="token keyword">return</span> email<span class="token punctuation">.</span><span class="token function">substring</span><span class="token punctuation">(</span><span class="token number">0</span><span class="token punctuation">,</span> index<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>
           

}

• 1
• 2
• 3
• 4
• 5
• 6
• 7
• 8
• 9
• 10
• 11
• 12
• 13
• 14
• 15
• 16
• 17
• 18
• 19
• 20
• 21
• 22
• 23
• 24
• 25
• 26
• 27
• 28
• 29
• 30
• 31
• 32
• 33
• 34
• 35
• 36
• 37

練習題 : 分别通過for循環/While循環/do-While循環寫一個死循環

public class DeadCycle {

public static void main(String[] args) {

//for循環的死循環

// for (int i = 1; ; i++){

// System.out.println(“歡迎學習泡泡的分享,繼續加油哦~”);

// }

//while循環的死循環

// while(true){

// System.out.println(“都到這裡啦?奧利給~”);

// }

//do-while循環的死循環

do{

System.out.println(“相信我們可以的~”);

}while(true);

}

}

• 1
• 2
• 3
• 4
• 5
• 6
• 7
• 8
• 9
• 10
• 11
• 12
• 13
• 14
• 15
• 16
• 17
• 18

練習題: 雞兔同籠問題(窮舉法)

已知:雞兔共35隻,共94隻腳,那麼雞和兔各幾隻?
package cn.cxy.exec;
//窮舉法
//雞    兔
//0     35
//1     34
//2     33
//3     32
//...
//23    12
//...
//35    0
public class SameCage {
    public static void main(String[] args) {
        //循環變量j,控制小雞的個數: 0到35遞增
        //循環變量t,控制兔子的個數: 35到0遞減
        for(int j=0,t=35; j<=35; j++,t--) {//如果有多個小條件,用逗号隔開
            //保證腳的數量是94
            if(j*2 + t*4 == 94) {
                System.out.println("雞："+j+"， 兔："+t);
            }
        }
    }
}
           

• 1
• 2
• 3
• 4
• 5
• 6
• 7
• 8
• 9
• 10
• 11
• 12
• 13
• 14
• 15
• 16
• 17
• 18
• 19
• 20
• 21
• 22
• 23
• 24

練習題:商品錄入系統

通過java基礎的相關知識，設計并完成一個簡單的商品錄入系統，可以實作：菜單顯示、商品資訊展示、商品資訊錄入、商品資訊查詢、退出的功能

import java.util.Scanner;

public class Product {

//成員變量

static String[] names = { “iPhoneXS”,“華為 Mate 20 pro”,“小米X”,“vivo NEX”,“oppo Find”};

static double[] price = { 8999,5399,2399,4399,3999};

static int[] numbers = { 50,20,80,120,90};

public static void main(String[] args) {

<span class="token comment">//死循環顯示菜單</span>
  outer<span class="token operator">:</span>
  <span class="token keyword">while</span><span class="token punctuation">(</span><span class="token boolean">true</span><span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
     <span class="token comment">//顯示菜單，并獲得選擇的值</span>
     <span class="token keyword">int</span> c <span class="token operator">=</span> <span class="token function">menu</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
     <span class="token comment">//判斷c的值</span>
     <span class="token keyword">switch</span><span class="token punctuation">(</span>c<span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
     <span class="token keyword">case</span> <span class="token number">1</span><span class="token operator">:</span> <span class="token function">f1</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">break</span><span class="token punctuation">;</span>
     <span class="token keyword">case</span> <span class="token number">2</span><span class="token operator">:</span> <span class="token function">f2</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">break</span><span class="token punctuation">;</span>
     <span class="token keyword">case</span> <span class="token number">3</span><span class="token operator">:</span> <span class="token function">f3</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">break</span><span class="token punctuation">;</span>
     <span class="token keyword">case</span> <span class="token number">4</span><span class="token operator">:</span> <span class="token function">f4</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">break</span><span class="token punctuation">;</span>
     <span class="token keyword">case</span> <span class="token number">5</span><span class="token operator">:</span> <span class="token keyword">break</span> outer<span class="token punctuation">;</span>
     <span class="token punctuation">}</span>
  <span class="token punctuation">}</span>
           

}

private static int menu() {

System.out.println("----------------------");

System.out.println(“1. 商品清單”);

System.out.println(“2. 商品錄入”);

System.out.println(“3. 商品查詢”);

System.out.println(“4. 統計資訊”);

System.out.println(“5. 退出”);

System.out.println("----------------------");

System.out.print("選擇：> ");

return new Scanner(System.in).nextInt();

}

private static void f1() {

for(int i=0;i<names.length;i++) {

String n = names[i];

double p = price[i];

int b = numbers[i];

System.out.println(

(i+1)+". 名稱："+n+"，價格："+p+"，數量："+b);

}

}

private static void f2() {

//周遊數組

for (int i = 0; i < names.length; i++) {

System.out.println(“錄入第”+(i+1)+“件商品：”);

System.out.print(“名稱：”);

String n = new Scanner(System.in).nextLine();

System.out.print(“價格：”);

double p = new Scanner(System.in).nextDouble();

System.out.print(“數量：”);

int b = new Scanner(System.in).nextInt();

names[i] = n;

price[i] = p;

numbers[i] = b;

}

//重新顯示商品清單

f1();

}

private static void f3() {

System.out.print(“輸入查詢的商品名：”);

String n = new Scanner(System.in).nextLine();

//周遊數組

for (int i = 0; i < names.length; i++) {

// n 和 names[i] 相等

if(n.equals(names[i])) {

String name = names[i];

double p = price[i];

int b = numbers[i];

System.out.println(

(i+1)+". 名稱："+name+"，價格："+p+"，數量："+b);

return;

}

}

//循環結束，所有商品都比較完，沒有找到

System.out.println(“找不到商品”);

}

private static void f4() {

/*

names

[“A”, “B”, “C”]

price

[2, 8, 3]

numbers

[200, 300, 180]

0 1 2

/

//商品總價，單價均價，最高單價，最高總價

double spzj = 0;//商品總價

double djzj = 0;//單價總價

double zgdj = 0;//最高單價

double zgzj = 0;//最高總價

//周遊數組

for (int i = 0; i < names.length; i++) {

spzj += price[i] numbers[i];

djzj += price[i];

//數組中，找到更大的值

if(price[i] > zgdj) {

zgdj = price[i];//更大值存到這個變量

}

if(price[i]numbers[i] > zgzj) {

zgzj = price[i]numbers[i];

}

}

System.out.println(“商品總價：”+spzj);

System.out.println(“單價均價：”+(djzj/names.length));

System.out.println(“最高單價：”+zgdj);

System.out.println(“最高總價：”+zgzj);

}

}

• 1
• 2
• 3
• 4
• 5
• 6
• 7
• 8
• 9
• 10
• 11
• 12
• 13
• 14
• 15
• 16
• 17
• 18
• 19
• 20
• 21
• 22
• 23
• 24
• 25
• 26
• 27
• 28
• 29
• 30
• 31
• 32
• 33
• 34
• 35
• 36
• 37
• 38
• 39
• 40
• 41
• 42
• 43
• 44
• 45
• 46
• 47
• 48
• 49
• 50
• 51
• 52
• 53
• 54
• 55
• 56
• 57
• 58
• 59
• 60
• 61
• 62
• 63
• 64
• 65
• 66
• 67
• 68
• 69
• 70
• 71
• 72
• 73
• 74
• 75
• 76
• 77
• 78
• 79
• 80
• 81
• 82
• 83
• 84
• 85
• 86
• 87
• 88
• 89
• 90
• 91
• 92
• 93
• 94
• 95
• 96
• 97
• 98
• 99
• 100
• 101
• 102
• 103
• 104
• 105
• 106
• 107
• 108
• 109
• 110
• 111
• 112
• 113
• 114
• 115
• 116
• 117
• 118
• 119
• 120
• 121
• 122
• 123
• 124
• 125
• 126
• 127
• 128
• 129
• 130
• 131
• 132
• 133
• 134
• 135
• 136
• 137
• 138
• 139
• 140
• 141
• 142
• 143
• 144
• 145
• 146
• 147
• 148
• 149
• 150
• 151
• 152
• 153
• 154
• 155
• 156
• 157
• 158
• 159
• 160
• 161
• 162
• 163

練習題:求數字階乘(for循環版)

需求:接收使用者輸入的數字,計算該數字的階乘結果

已知:負數不可以有階乘,0的階乘結果是1,

5 ! = 5 x 4 x 3 x 2 x 1

import java.util.Scanner;

public class Factorial {

public static void main(String[] args) {

System.out.print(“輸入整數，求階乘：”);

int n = new Scanner(System.in).nextInt();

//調用f()方法，把n的值傳遞到f()方法，求階乘

f(n);

}

<span class="token keyword">public</span> <span class="token keyword">static</span> <span class="token keyword">void</span> <span class="token function">f</span><span class="token punctuation">(</span><span class="token keyword">int</span> n<span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
    <span class="token keyword">if</span><span class="token punctuation">(</span>n<span class="token operator">&lt;</span><span class="token number">0</span><span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
        <span class="token class-name">System</span><span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span><span class="token string">"負數不可以求階乘"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
        <span class="token keyword">return</span><span class="token punctuation">;</span><span class="token comment">//方法結束，傳回到調用位置繼續執行</span>
    <span class="token punctuation">}</span>
    <span class="token keyword">if</span><span class="token punctuation">(</span>n <span class="token operator">==</span> <span class="token number">0</span><span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
        <span class="token class-name">System</span><span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span><span class="token string">"0的階乘是1"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
        <span class="token keyword">return</span><span class="token punctuation">;</span>
    <span class="token punctuation">}</span>
    <span class="token comment">/*
     * r = 5
     * i
     * 4, r=r*i
     * 3, r=r*i
     * 2, r=r*i
     * 1, r=r*i
     */</span>
    <span class="token keyword">long</span> r <span class="token operator">=</span> n<span class="token punctuation">;</span>
    <span class="token keyword">for</span><span class="token punctuation">(</span><span class="token keyword">int</span> i<span class="token operator">=</span>n<span class="token operator">-</span><span class="token number">1</span><span class="token punctuation">;</span> i<span class="token operator">&gt;=</span><span class="token number">1</span><span class="token punctuation">;</span> i<span class="token operator">--</span><span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
        r <span class="token operator">*=</span> i<span class="token punctuation">;</span>
    <span class="token punctuation">}</span>
    <span class="token class-name">System</span><span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span>n<span class="token operator">+</span><span class="token string">"的階乘："</span><span class="token operator">+</span>r<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>
           

}

• 1
• 2
• 3
• 4
• 5
• 6
• 7
• 8
• 9
• 10
• 11
• 12
• 13
• 14
• 15
• 16
• 17
• 18
• 19
• 20
• 21
• 22
• 23
• 24
• 25
• 26
• 27
• 28
• 29
• 30
• 31
• 32
• 33
• 34
• 35
• 36
• 37

練習題:多次生成随機數,并列印第一次出現大于0.999 時的次數與生成的随機數

public class ForBreak {

public static void main(String[] args) {

// Math.random()可以産生[0,1)的随機浮點數

// >0.999

//寫一個死循環, i變量用來計次

for(int i=1; ;i++) {

double d = Math.random();

if(d>0.999) {

System.out.println(“第”+i+“次産生了目标值,值為:”+d);

break;

}

}

}

}

• 1
• 2
• 3
• 4
• 5
• 6
• 7
• 8
• 9
• 10
• 11
• 12
• 13
• 14
• 15
• 16

練習題:列印100以内除了尾數為3,5,7的所有數

public class ForContinue {

public static void main(String[] args) {

for(int i=1;i<=100;i++) {

int y = i%10;//100以内的數,通過取餘求出尾數

if(y3 || y5 || y==7) {

continue;//如果尾數為3 5 7 ,則跳過後面的列印,進行下一輪循環

}

System.out.println(i);

}

}

}

• 1
• 2
• 3
• 4
• 5
• 6
• 7
• 8
• 9
• 10
• 11
• 12
• 13

練習題:求質數:接收使用者輸入的數字,判斷是否為質數

質數的概念:一個大于1的自然數,除了1和它自身外,不能被其他自然數整除的數叫做質數,也稱為素數

規定:1既不是質數,也不是合數

import java.util.Scanner;

public class PrimeNumber {

public static void main(String[] args) {

System.out.print(“請輸入要判斷的自然數：”);

int n = new Scanner(System.in).nextInt();

//調用getPrimeNumber()方法，判斷n是否為質數

getPrimeNumber(n);

}

public static void getPrimeNumber(int n) {

if(n<2) { //此範圍内的數均不為質數

System.out.println(n+“不是質數”);

return;//結束程式

}

if(n == 2) {

System.out.println(“2是質數”);

return;

}

//在 2到 1+n開方範圍(數學理論)，找能把n整除的值(這個值也稱作因子)

//如果找到可以把n整除的第三個數，那n就不是質數,反之,n為質數

double max = 1+ Math.sqrt(n);//max儲存的是查找因子的範圍

<span class="token comment">//依次周遊範圍内的所有數,驗證是否存在n的因子</span>
    <span class="token keyword">for</span><span class="token punctuation">(</span><span class="token keyword">int</span> i<span class="token operator">=</span><span class="token number">2</span><span class="token punctuation">;</span> i<span class="token operator">&lt;</span>max<span class="token punctuation">;</span> i<span class="token operator">++</span><span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
        <span class="token comment">//判斷n能不能被i整除,如果有,說明不是質數</span>
        <span class="token keyword">if</span><span class="token punctuation">(</span>n<span class="token operator">%</span>i <span class="token operator">==</span> <span class="token number">0</span><span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
            <span class="token class-name">System</span><span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span>n<span class="token operator">+</span><span class="token string">"不是質數"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
            <span class="token keyword">return</span><span class="token punctuation">;</span>
        <span class="token punctuation">}</span>
    <span class="token punctuation">}</span>
    <span class="token comment">//如果判斷了範圍内的所有值，沒有能整除的,則說明n是質數</span>
    <span class="token class-name">System</span><span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span>n<span class="token operator">+</span><span class="token string">"是質數"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>
           

}

• 1
• 2
• 3
• 4
• 5
• 6
• 7
• 8
• 9
• 10
• 11
• 12
• 13
• 14
• 15
• 16
• 17
• 18
• 19
• 20
• 21
• 22
• 23
• 24
• 25
• 26
• 27
• 28
• 29
• 30
• 31
• 32
• 33
• 34
• 35
• 36

練習題:接收使用者輸入的數字,判斷在此範圍内質數的個數

import java.util.Scanner;

public class CountPrimeNumber {

public static void main(String[] args) {

System.out.println(“輸入整數n，求n内質數的數量”);

int n = new Scanner(System.in).nextInt();

<span class="token function">count</span><span class="token punctuation">(</span>n<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>

<span class="token keyword">public</span> <span class="token keyword">static</span> <span class="token keyword">void</span> <span class="token function">count</span><span class="token punctuation">(</span><span class="token keyword">int</span> n<span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
    <span class="token keyword">if</span><span class="token punctuation">(</span>n<span class="token operator">&lt;</span><span class="token number">2</span><span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
        <span class="token class-name">System</span><span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span><span class="token string">"沒有質數"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
        <span class="token keyword">return</span><span class="token punctuation">;</span>
    <span class="token punctuation">}</span>
    <span class="token keyword">if</span><span class="token punctuation">(</span>n<span class="token operator">==</span><span class="token number">2</span><span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
        <span class="token class-name">System</span><span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span><span class="token string">"有1個質數"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
        <span class="token keyword">return</span><span class="token punctuation">;</span>
    <span class="token punctuation">}</span>
    <span class="token comment">//定義計數變量</span>
    <span class="token keyword">int</span> count <span class="token operator">=</span> <span class="token number">1</span><span class="token punctuation">;</span><span class="token comment">//已知有一個質數</span>
    outer<span class="token operator">:</span>   <span class="token comment">//從3到n尋找質數</span>
    <span class="token keyword">for</span><span class="token punctuation">(</span><span class="token keyword">int</span> i<span class="token operator">=</span><span class="token number">3</span><span class="token punctuation">;</span> i<span class="token operator">&lt;=</span>n <span class="token punctuation">;</span>i<span class="token operator">++</span><span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
        <span class="token comment">//判斷i是否是質數</span>
        <span class="token keyword">double</span> max <span class="token operator">=</span> <span class="token number">1</span><span class="token operator">+</span> <span class="token class-name">Math</span><span class="token punctuation">.</span><span class="token function">sqrt</span><span class="token punctuation">(</span>i<span class="token punctuation">)</span><span class="token punctuation">;</span>
        <span class="token keyword">for</span><span class="token punctuation">(</span><span class="token keyword">int</span> j<span class="token operator">=</span><span class="token number">2</span><span class="token punctuation">;</span> j<span class="token operator">&lt;</span>max<span class="token punctuation">;</span> j<span class="token operator">++</span><span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span><span class="token comment">//在2到&lt;max，找能把i整除的數</span>
            <span class="token keyword">if</span><span class="token punctuation">(</span>i<span class="token operator">%</span>j <span class="token operator">==</span> <span class="token number">0</span><span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span><span class="token comment">//i被j整除，i不是質數</span>
                <span class="token comment">//跳到i++，繼續判斷下一個i值</span>
                <span class="token keyword">continue</span> outer<span class="token punctuation">;</span><span class="token comment">//跳到外部outer的位置</span>
            <span class="token punctuation">}</span>
        <span class="token punctuation">}</span>
        <span class="token comment">//内層j循環結束，i是質數</span>
        count<span class="token operator">++</span><span class="token punctuation">;</span>
    <span class="token punctuation">}</span>
    <span class="token class-name">System</span><span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span>n<span class="token operator">+</span><span class="token string">"内質數的數量："</span><span class="token operator">+</span>count<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>
           

}

• 1
• 2
• 3
• 4
• 5
• 6
• 7
• 8
• 9
• 10
• 11
• 12
• 13
• 14
• 15
• 16
• 17
• 18
• 19
• 20
• 21
• 22
• 23
• 24
• 25
• 26
• 27
• 28
• 29
• 30
• 31
• 32
• 33
• 34
• 35
• 36
• 37
• 38
• 39

練習題:生成一個順序數組,将這個數組的元素打亂順序後輸出

import java.util.Arrays;

import java.util.Random;

public class ShuffleArray {

public static void main(String[] args) {

//調用f()方法，從方法擷取一個int[]數組

int[] a = f();

//周遊列印數組資料

for(int i=0; i<a.length; i++) {

System.out.println(a[i]);

}

System.out.println("\n\n----------------");

<span class="token comment">//把a數組，傳遞到 shuffle() 方法打亂順序</span>
    <span class="token function">shuffle</span><span class="token punctuation">(</span>a<span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token comment">//列印亂序後的數組</span>
    <span class="token class-name">System</span><span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span><span class="token class-name">Arrays</span><span class="token punctuation">.</span><span class="token function">toString</span><span class="token punctuation">(</span>a<span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>

<span class="token keyword">public</span> <span class="token keyword">static</span> <span class="token keyword">int</span><span class="token punctuation">[</span><span class="token punctuation">]</span> <span class="token function">f</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
    <span class="token comment">//建立int[]數組，長度5</span>
    <span class="token comment">//再把它的記憶體位址存到變量 a</span>
    <span class="token keyword">int</span><span class="token punctuation">[</span><span class="token punctuation">]</span> a <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token keyword">int</span><span class="token punctuation">[</span><span class="token number">5</span><span class="token punctuation">]</span><span class="token punctuation">;</span>
    <span class="token comment">//周遊通路5個位置，填入1,2,3,4,5</span>
    <span class="token keyword">for</span><span class="token punctuation">(</span><span class="token keyword">int</span> i<span class="token operator">=</span><span class="token number">0</span><span class="token punctuation">;</span> i<span class="token operator">&lt;</span>a<span class="token punctuation">.</span>length<span class="token punctuation">;</span> i<span class="token operator">++</span><span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
        a<span class="token punctuation">[</span>i<span class="token punctuation">]</span> <span class="token operator">=</span> i<span class="token operator">+</span><span class="token number">1</span><span class="token punctuation">;</span>
    <span class="token punctuation">}</span>
    <span class="token comment">//傳回數組，把數組傳回到調用位置</span>
    <span class="token comment">//本質是把數組位址傳回去</span>
    <span class="token keyword">return</span> a<span class="token punctuation">;</span>
<span class="token punctuation">}</span>

<span class="token keyword">public</span> <span class="token keyword">static</span> <span class="token keyword">void</span> <span class="token function">shuffle</span><span class="token punctuation">(</span><span class="token keyword">int</span><span class="token punctuation">[</span><span class="token punctuation">]</span> a<span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
    <span class="token comment">/*
     *        j
     * [4, 2, 3, 1, 5]
     *     i
     *
     * *) i循環周遊數組
     * *) 随機定位下标j與i交換
     */</span>
    <span class="token keyword">for</span> <span class="token punctuation">(</span><span class="token keyword">int</span> i <span class="token operator">=</span> <span class="token number">0</span><span class="token punctuation">;</span> i <span class="token operator">&lt;</span> a<span class="token punctuation">.</span>length<span class="token punctuation">;</span> i<span class="token operator">++</span><span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
        <span class="token comment">//随機下标j，範圍：[0, a.length)</span>
        <span class="token keyword">int</span> j <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">Random</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">nextInt</span><span class="token punctuation">(</span>a<span class="token punctuation">.</span>length<span class="token punctuation">)</span><span class="token punctuation">;</span>
        <span class="token keyword">int</span> t <span class="token operator">=</span> a<span class="token punctuation">[</span>i<span class="token punctuation">]</span><span class="token punctuation">;</span>
        a<span class="token punctuation">[</span>i<span class="token punctuation">]</span> <span class="token operator">=</span> a<span class="token punctuation">[</span>j<span class="token punctuation">]</span><span class="token punctuation">;</span>
        a<span class="token punctuation">[</span>j<span class="token punctuation">]</span> <span class="token operator">=</span> t<span class="token punctuation">;</span>
    <span class="token punctuation">}</span>
<span class="token punctuation">}</span>
           

}

• 1
• 2
• 3
• 4
• 5
• 6
• 7
• 8
• 9
• 10
• 11
• 12
• 13
• 14
• 15
• 16
• 17
• 18
• 19
• 20
• 21
• 22
• 23
• 24
• 25
• 26
• 27
• 28
• 29
• 30
• 31
• 32
• 33
• 34
• 35
• 36
• 37
• 38
• 39
• 40
• 41
• 42
• 43
• 44
• 45
• 46
• 47
• 48
• 49
• 50
• 51
• 52

練習題:列印全三角形

需求:接收使用者輸入的行數,列印對應的全三角形,如圖所示:

import java.util.Scanner;

public class PrintTraingle {

public static void main(String[] args) {

//1.提示并接收使用者輸入的行數:

System.out.println(“請輸入您要列印星星的行數:”);

int n = new Scanner(System.in).nextInt();

<span class="token comment">//2.開始列印圖形</span>
	<span class="token comment">//2.1外層循環控制列印的行數 i的取值範圍:[1,n],一共n行</span>
	<span class="token keyword">for</span><span class="token punctuation">(</span><span class="token keyword">int</span> i<span class="token operator">=</span><span class="token number">1</span><span class="token punctuation">;</span>i<span class="token operator">&lt;=</span>n<span class="token punctuation">;</span>i<span class="token operator">++</span><span class="token punctuation">)</span><span class="token punctuation">{<!-- --></span>
		<span class="token comment">//2.2内層循環1</span>
		<span class="token comment">//控制每行列印空格的個數 j的取值範圍:[0,n-i),即1 2 3...</span>
		<span class="token keyword">for</span><span class="token punctuation">(</span><span class="token keyword">int</span> j<span class="token operator">=</span><span class="token number">0</span><span class="token punctuation">;</span>j<span class="token operator">&lt;</span>n<span class="token operator">-</span>i<span class="token punctuation">;</span>j<span class="token operator">++</span><span class="token punctuation">)</span><span class="token punctuation">{<!-- --></span>
			<span class="token class-name">System</span><span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">print</span><span class="token punctuation">(</span><span class="token string">" "</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
		<span class="token punctuation">}</span>
		<span class="token comment">//2.3内層循環2</span>
		<span class="token comment">//控制每行列印星星的個數 k的取值範圍:[1,2*i-1],即1 3 5 ...</span>
		<span class="token keyword">for</span><span class="token punctuation">(</span><span class="token keyword">int</span> k<span class="token operator">=</span><span class="token number">1</span><span class="token punctuation">;</span>k<span class="token operator">&lt;=</span><span class="token number">2</span><span class="token operator">*</span>i<span class="token operator">-</span><span class="token number">1</span><span class="token punctuation">;</span>k<span class="token operator">++</span><span class="token punctuation">)</span><span class="token punctuation">{<!-- --></span>
			<span class="token class-name">System</span><span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">print</span><span class="token punctuation">(</span><span class="token string">"*"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
		<span class="token punctuation">}</span>
		<span class="token comment">//2.4列印完本行所有内容後添加換行</span>
		<span class="token class-name">System</span><span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token punctuation">}</span>
<span class="token punctuation">}</span>
           

}

• 1
• 2
• 3
• 4
• 5
• 6
• 7
• 8
• 9
• 10
• 11
• 12
• 13
• 14
• 15
• 16
• 17
• 18
• 19
• 20
• 21
• 22
• 23
• 24
• 25
• 26
• 27
• 28

練習題：模拟雙色球生成案例

需求：體彩中有一項是雙色球，要求在1-33号共33個紅色球裡選出6個，1-16号共16個藍色球中選出一個作為中獎号碼，請實作這個需求

import java.util.Arrays;

import java.util.Random;

public class ColorBall {

public static void main(String[] args) {

//準備兩個号碼數組

int[] r = zbsz(33);//[1,2,3,4,5…33]

int[] b = zbsz(16);//[1,2,3…16]

System.out.println(Arrays.toString(r));

System.out.println(Arrays.toString(b));

//選擇紅球

int[] red = selectRed(r);

//選擇藍球

int blue = selectBlue(b);

System.out.println(“紅球：”+Arrays.toString(red));

System.out.println(“藍球：”+blue);

}

private static int[] zbsz(int n) { //準備數組的方法

//建立n個長度的int[]數組，存到a

int[] a = new int[n];

//周遊a數組，填入1到n

for (int i = 0; i < a.length; i++) {

a[i] = i+1;

}

//傳回數組

return a;

}

private static int[] selectRed(int[] r) { //選擇紅球

//i循環從0到<6

for (int i = 0; i < 6; i++) {

//j随機定位

int j =

i+ new Random().nextInt(r.length-i);

int t = r[i];

r[i] = r[j];

r[j] = t;

}

//截取前6個位置，生成一個新數組傳回

return Arrays.copyOf(r, 6);

}

private static int selectBlue(int[] b) { //選擇藍球

return b[new Random().nextInt(16)];

}

}

• 1
• 2
• 3
• 4
• 5
• 6
• 7
• 8
• 9
• 10
• 11
• 12
• 13
• 14
• 15
• 16
• 17
• 18
• 19
• 20
• 21
• 22
• 23
• 24
• 25
• 26
• 27
• 28
• 29
• 30
• 31
• 32
• 33
• 34
• 35
• 36
• 37
• 38
• 39
• 40
• 41
• 42
• 43
• 44
• 45
• 46
• 47
• 48
• 49
• 50
• 51
• 52
• 53
• 54

練習題:求任意自然數各位數之和

接收使用者輸入的任意自然數,累計所有位數數字之和

需求:接收使用者輸入的行數,

import java.util.Scanner;

public class SumNum {

public static void main(String[] args) {

//1.提示并接收使用者要計算的自然數:

System.out.println(“請輸出您要求和的自然數:”);

int n = new Scanner(System.in).nextInt();

//2.定義一個變量用來儲存最終求和的結果

int sum=0;

//3.循環擷取每一位上的數

while(n!=0){

//4.求目前的個位數,并将個位數累加

sum = sum + (n%10);

//5.去掉剛剛累加過的最後一位數,得到新的整數

//比如剛剛的十位就變成了現在的個位

n=n/10;

}

//6.列印最終的結果:

System.out.println(sum);

}

}

• 1
• 2
• 3
• 4
• 5
• 6
• 7
• 8
• 9
• 10
• 11
• 12
• 13
• 14
• 15
• 16
• 17
• 18
• 19
• 20
• 21
• 22
• 23
• 24

練習題:求任意數組中所有元素的最大值

public class GetArrayMaxNum {

public static void main(String[] args) {

//1.定義一個數組

int[] arr={ 90,1562,43,2,44,8,6666};

//2.選取數組中的第一個元素開始比較

int max=arr[0];

//3.依次周遊數組中的每個元素

for(int i=1;i<arr.length;i++){ //i指的是下标,我們通過下标來操作數組中的元素

//4.判斷目前元素與目前最大值的大小

if(arr[i]>max){

//5.如果目前數組元素大于max,就講此元素的值指派給max

max=arr[i];

}

}

//6.列印最終的結果

System.out.println(max);

}

}

• 1
• 2
• 3
• 4
• 5
• 6
• 7
• 8
• 9
• 10
• 11
• 12
• 13
• 14
• 15
• 16
• 17
• 18
• 19
• 20

練習題:求1000以内的完數

完數:如果一個數等于其所有因子之和,我們就稱這個數為"完數",比如6的因子為1,2,3 6 = 1 + 2 + 3,那麼6就是一個完數

package cn.cxy.exec;
/**擷取1000以内的完數*/
public class GetNum {
	public static void main(String[] args) {
		//1.循環周遊1000以内的所有數
		for(int i=1;i<=1000;i++){
			//2.定義一個變量來儲存求和的結果
			int sum = 0;
			//3.求i的因子
			for(int j=1;j<=i/2;j++){
				//4.判斷是否能被整除
				if(i % j == 0){
					//5.如果能整除,就是因子,因子需要累加
					sum+=j;
				}
			}
			//6.如果因子累加之和為本輪判斷的數,則目前數是完數,輸出
			if(sum==i){
				System.out.println(i);
            
<span class="token punctuation">}</span>
	<span class="token punctuation">}</span>
<span class="token punctuation">}</span>
           
   

}

• 1
• 2
• 3
• 4
• 5
• 6
• 7
• 8
• 9
• 10
• 11
• 12
• 13
• 14
• 15
• 16
• 17
• 18
• 19
• 20
• 21
• 22
• 23
• 24

練習題： 随機數組的歸并問題

需求：生成兩個任意的随機數組，并将這兩個數組按照數字大小按順序歸并到一個新數組中

import java.util.Arrays;

import java.util.Random;

import java.util.Scanner;

public class MergingArrays {

public static void main(String[] args) {

int[] a = suiJi();

int[] b = suiJi();

Arrays.sort(a);

Arrays.sort(b);

System.out.println(Arrays.toString(a));

System.out.println(Arrays.toString(b));

int[] c = heBing(a, b);

System.out.println(Arrays.toString(c));

}

<span class="token keyword">private</span> <span class="token keyword">static</span> <span class="token keyword">int</span><span class="token punctuation">[</span><span class="token punctuation">]</span> <span class="token function">suiJi</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
      <span class="token keyword">int</span> n <span class="token operator">=</span> <span class="token number">5</span><span class="token operator">+</span> <span class="token keyword">new</span> <span class="token class-name">Random</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">nextInt</span><span class="token punctuation">(</span><span class="token number">6</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
      <span class="token keyword">int</span><span class="token punctuation">[</span><span class="token punctuation">]</span> a <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token keyword">int</span><span class="token punctuation">[</span>n<span class="token punctuation">]</span><span class="token punctuation">;</span>
      <span class="token keyword">for</span> <span class="token punctuation">(</span><span class="token keyword">int</span> i <span class="token operator">=</span> <span class="token number">0</span><span class="token punctuation">;</span> i <span class="token operator">&lt;</span> a<span class="token punctuation">.</span>length<span class="token punctuation">;</span> i<span class="token operator">++</span><span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
         a<span class="token punctuation">[</span>i<span class="token punctuation">]</span> <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">Random</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">nextInt</span><span class="token punctuation">(</span><span class="token number">100</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
      <span class="token punctuation">}</span>
      <span class="token keyword">return</span> a<span class="token punctuation">;</span>
   <span class="token punctuation">}</span>

   <span class="token keyword">private</span> <span class="token keyword">static</span> <span class="token keyword">int</span><span class="token punctuation">[</span><span class="token punctuation">]</span> <span class="token function">heBing</span><span class="token punctuation">(</span><span class="token keyword">int</span><span class="token punctuation">[</span><span class="token punctuation">]</span> a<span class="token punctuation">,</span> <span class="token keyword">int</span><span class="token punctuation">[</span><span class="token punctuation">]</span> b<span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
      <span class="token comment">/*
       * a[1,1,2,3,4]
       *              j
       * b[1,2,4,5,6,8,9]
       *         k
       *
       * c[                     ]
       *               i
       */</span>
      <span class="token comment">//建立數組</span>
      <span class="token keyword">int</span><span class="token punctuation">[</span><span class="token punctuation">]</span> c <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token keyword">int</span><span class="token punctuation">[</span>a<span class="token punctuation">.</span>length<span class="token operator">+</span>b<span class="token punctuation">.</span>length<span class="token punctuation">]</span><span class="token punctuation">;</span>
      <span class="token comment">//對新數組周遊</span>
      <span class="token keyword">for</span><span class="token punctuation">(</span><span class="token keyword">int</span> i<span class="token operator">=</span><span class="token number">0</span><span class="token punctuation">,</span>j<span class="token operator">=</span><span class="token number">0</span><span class="token punctuation">,</span>k<span class="token operator">=</span><span class="token number">0</span><span class="token punctuation">;</span>i<span class="token operator">&lt;</span>c<span class="token punctuation">.</span>length<span class="token punctuation">;</span>i<span class="token operator">++</span><span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
         <span class="token keyword">if</span><span class="token punctuation">(</span>j<span class="token operator">&gt;=</span>a<span class="token punctuation">.</span>length<span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span><span class="token comment">//j越界，b數組資料一個一個放入新數組</span>
            <span class="token comment">//c[i] = b[k];</span>
            <span class="token comment">//k++;</span>
            <span class="token comment">//continue;</span>
            <span class="token class-name">System</span><span class="token punctuation">.</span><span class="token function">arraycopy</span><span class="token punctuation">(</span>b<span class="token punctuation">,</span>k<span class="token punctuation">,</span>c<span class="token punctuation">,</span>i<span class="token punctuation">,</span>b<span class="token punctuation">.</span>length<span class="token operator">-</span>k<span class="token punctuation">)</span><span class="token punctuation">;</span>
            <span class="token keyword">break</span><span class="token punctuation">;</span>
         <span class="token punctuation">}</span> <span class="token keyword">else</span> <span class="token keyword">if</span><span class="token punctuation">(</span>k<span class="token operator">&gt;=</span>b<span class="token punctuation">.</span>length<span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span><span class="token comment">//k越界,a數組資料一個個放入新數組</span>
            <span class="token comment">//c[i] = a[j];</span>
            <span class="token comment">//j++;</span>
            <span class="token comment">//continue;</span>
            <span class="token class-name">System</span><span class="token punctuation">.</span><span class="token function">arraycopy</span><span class="token punctuation">(</span>a<span class="token punctuation">,</span>j<span class="token punctuation">,</span>c<span class="token punctuation">,</span>i<span class="token punctuation">,</span>a<span class="token punctuation">.</span>length<span class="token operator">-</span>j<span class="token punctuation">)</span><span class="token punctuation">;</span>
            <span class="token keyword">break</span><span class="token punctuation">;</span>
         <span class="token punctuation">}</span>
         <span class="token comment">//j和k，較小值放入i位置，并遞增</span>
         <span class="token keyword">if</span><span class="token punctuation">(</span>a<span class="token punctuation">[</span>j<span class="token punctuation">]</span><span class="token operator">&lt;=</span>b<span class="token punctuation">[</span>k<span class="token punctuation">]</span><span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
            c<span class="token punctuation">[</span>i<span class="token punctuation">]</span> <span class="token operator">=</span> a<span class="token punctuation">[</span>j<span class="token punctuation">]</span><span class="token punctuation">;</span>
            j<span class="token operator">++</span><span class="token punctuation">;</span>
         <span class="token punctuation">}</span> <span class="token keyword">else</span> <span class="token punctuation">{<!-- --></span>
            c<span class="token punctuation">[</span>i<span class="token punctuation">]</span> <span class="token operator">=</span> b<span class="token punctuation">[</span>k<span class="token punctuation">]</
           

JAVA小白程式設計題練習

可能有很多剛入門的小白不知道自己如何能快速提升程式設計技巧與熟練度

其實大佬進階之路隻有一個~ 那就是瘋狂碼代碼!!!實踐出真知!!!

是以為了大家能夠想練習的時候有素材,泡泡給大家整理了一些練習題

由于平時比較忙,是以我在不定時努力更新中,歡迎監督~

500是立的Flag啊哈哈哈哈,我們共同努力吧,本帖已滿,以下為第二個練習帖的連結：

練習帖2 點我點我

希望能給大家帶來幫助~ 😃😃😃

文章目錄

• JAVA小白程式設計題練習
• • • [練習帖2 點我點我](https://chengxiaoyu-paopao.blog.csdn.net/article/details/118485298)
    • • • 希望能給大家帶來幫助~ :):):)
    • 練習題:通過代碼編寫，輸出一句話：“我要開始學習JAVA了，今天又是知識量滿滿的一天~”
    • 練習題：列印個人資訊案例，将一個人的一些個人資訊列印輸出
    • 練習題：拼接列印：輸出：XXX：這是我學習JAVA的第X年，我的期望薪資是XXX
    • 練習題：定義兩個整數，計算這兩個整數加減乘除運算的結果，并把結果列印到控制台
    • 練習題：預測身高案例：
    • 練習題：邏輯判斷
    • 練習題：最優選擇
    • 練習題: 接收使用者輸入的3個整數,并将它們的最大值作為結果輸出
    • 練習題: BMI 指數測試 BMI = 體重 (kg) / 身高² (m)
    • 練習題：最優選擇2
    • 練習題：求數字的絕對值
    • 練習題：求指定兩個數的最大公約數和最小公倍數
    • 練習題：銀行收入計算
    • 練習題：求稅後工資問題
    • 練習題: 手機選号:根據使用者輸入的手機号來确認使用者實際支付的價格
    • 練習題: 擷取郵箱名字
    • 練習題 : 分别通過for循環/While循環/do-While循環寫一個死循環
    • 練習題: 雞兔同籠問題(窮舉法)
    • 練習題:商品錄入系統
    • 練習題:求數字階乘(for循環版)
    • 練習題:多次生成随機數,并列印第一次出現大于0.999 時的次數與生成的随機數
    • 練習題:列印100以内除了尾數為3,5,7的所有數
    • 練習題:求質數:接收使用者輸入的數字,判斷是否為質數
    • 練習題:接收使用者輸入的數字,判斷在此範圍内質數的個數
    • 練習題:生成一個順序數組,将這個數組的元素打亂順序後輸出
    • 練習題:列印全三角形
    • 練習題：模拟雙色球生成案例
    • 練習題:求任意自然數各位數之和
    • 練習題:求任意數組中所有元素的最大值
    • 練習題:求1000以内的完數
    • 練習題： 随機數組的歸并問題
    • 練習題：周遊二維數組打油詩
    • 練習題:求猴子大王
    • 練習題:斐波那契問題
    • 練習題:古典問題：生兔兔問題
    • 練習題:列印水仙花數
    • 練習題：面向對象 封裝百分制分數
    • • • 分數類：
        • 測試類：
    • 練習題:面向對象 列印圖形
    • • • 形狀類【父類】：
        • 圓形類【子類】：
        • 方形類【子類】：
        • 直線類【子類】：
        • 測試類：随機生成圖形
    • 練習題:面向對象 設計士兵類
    • • • 士兵類：
        • 武器類：
        • 測試類1：
        • 測試類2：
    • 練習題:面向對象 設計寵物類
    • • • 寵物類【父類】：
        • 小貓類【子類】：
        • 小狗類【子類】：
        • 測試類：

練習題:通過代碼編寫，輸出一句話：“我要開始學習JAVA了，今天又是知識量滿滿的一天~”