方法的定义与调用

【实验七】

1、学习课本P64-67与方法有关的学习内容。

2、编写一个方法，判断该年份是平年还是闰年。

import java.util.Scanner;
public class Seven1 {
	public static void main(String[] args) {
		Scanner in = new Scanner(System.in);
		System.out.println("请输入年份");
		int b=in.nextInt();
		area(b);
		
	}
	public static void area(int a) {
		if((a%4==0&&a%100!=0)||a%400==0)
			System.out.println(a+"是闰年");
		else
			System.out.println(a+"不是闰年");
		
	}
}
           

3、通过自定义方法分别实现求长方形的面积、长方体的体积。

import java.util.Scanner;
public class Seven2 {
	public static void main(String[] args) {
		Scanner in = new Scanner(System.in);
		System.out.println("请输入长方形的长和宽");
		int a,b;
		a = in.nextInt();
		b = in.nextInt();
		int s =mian(a,b);
		System.out.println("这个长方形的面积是"+s);		
		System.out.println("请输入长方形的长宽高");
		int n1,n2,n3;
		n1 = in.nextInt();
		n2 = in.nextInt();
		n3 = in.nextInt();
		int v =ti(n1,n2,n3);
		System.out.println("这个长方体的体积是"+v);
	}
	public static int mian(int d,int l) {
		int s;
		s=d*l;
		return s;
	}
	public static int ti(int c,int k,int g) {
		int v = c*k*g;
		return v;
	}
}
           

4、通过自定义方法判断某数是否水仙花数。

import java.util.Scanner;
public class Seven3 {
	public static void main(String[] args) {
		int a,g;
		Scanner in = new Scanner(System.in);
		System.out.println("输入一个数");
		a = in.nextInt();
		shui(a);
	}
	public static void shui(int s) {
		int n1,n2,n3;
		n1 = s/100;
		n2 = s/10%10;
		n3 = s%10;
		if(n1*n1*n1+n2*n2*n2+n3*n3*n3==s)
			System.out.println(s+"是水仙花数");
		else
			System.out.println(s+"不是水仙花数");
	}
}
           

5、编写自定义方法，传递年份、月份，返回该月的天数。

import java.util.Scanner;
public class Seven4 {
	public static void main(String[] args) {
		Scanner in = new Scanner(System.in) ;
			System.out.println("输入年，月");
			int nian,yue;
			nian = in.nextInt();
			yue = in.nextInt();
			f(nian,yue);
	}
	public static void f(int a,int b) {	
			switch(b) {
			case 1:
			case 3:
			case 5:
			case 7:
			case 8:
			case 10:
			case 12:
				System.out.println("有31天");
				break;
			case 4:
			case 6:
			case 9:
			case 11:
				System.out.println("有30天");
				break;
			case 2:
				if((a%4==0&&a%100!=0)||a%400==0)
					System.out.println("有29天");
				else
					System.out.println("有28天");
			}
		
	}
}
           

6、编写一个方法，输出大于200的最小的质数。

public class Seven5 {
	public static void main(String[] args) {
		f();
	}
	static void f() {
		int a = 201;
		for(; ; a++) {
			boolean i = true;
			for(int j = 2;j<a;j++) {
				if(a%j==0) {
					i = false;
					break;
				}
			}
			if(i == true) {
				System.out.println(a);
				break;
			}
		}
	}
}
           

7、借用方法的嵌套调用实现求长方体的体积。

import java.util.Scanner;
public class Seven6 {
	public static void main(String[] args) {
		Scanner in = new Scanner(System.in);
		System.out.println("输入长宽高");
		int a,b,c,v;
		a = in.nextInt();
		b = in.nextInt();
		c = in.nextInt();
		v = ti(a,b,c);
		System.out.println("体积是"+v);
	}
	static int ti(int a1,int b1,int c1) {
		return(c1 * mian(a1,b1));
	}
	static int mian(int a2,int b2) {
		return a2*b2;
	}
}
           

8、借用递归实现求n!.

public class Seven7 {
	public static void main(String[] args) {
		int n = 7;
		int jc = f(n);
		System.out.println(n+"!"+"="+jc);
	}
	static int f(int a) {
		if(a==0 || a==1)
			return 1;
		else 
			return f(a-1)*a;
	}
}