Lesson_for_java_day10--練習

練習一：

package sonyi;
/*
	練習:
		定義一個表示學生的類。屬性有：學号，姓名，年齡，計算機成績，數學成績，英語成績。
		要求學号為類變量，每次增加學生時，學号自動增加，并指派給新增學生。計算學生的平均成績和總成績。
		執行個體化幾個對象，并測試。
*/
public class StudentTest {
	public static void main(String[] args) {
		
		//建立學生類，學号自動增加，其他參數由構造方法傳入
		Student s1 = new Student("zhangsan",20,95,80,78);
		Student s2 = new Student("lisi",20,95,80,78);
		System.out.println(s1);//列印對象就是列印對象的toString方法。
		System.out.println(s2);
		
		//設定學生學号從10開始
		Student.index = 10;
		Student s3 = new Student("lisi",27,95,80,78);
		System.out.println(s3);	
		Student s4 = new Student("lisi",27,95,80,78);
		System.out.println(s4);	
	}
}

class Student{
	static int index = 1;//定義一個靜态變量，用來記錄目前新增學生的學号
	//定義私有成員變量
	private String name;
	private int age;
	private int num;
	private double computerScore;
	private double mathScore;
	private double englisdScore;
	
	Student(){	
	}
		
	//重載構造方法，傳入實參
	Student(String name,int age,double computerScore,double mathScore,double englisdScore){
		this.name= name;
		this.age = age;
		this.computerScore = computerScore;
		this.mathScore = mathScore;
		this.englisdScore = englisdScore;	
		num = index++;//将目前學号賦給目前建立的學生對象，并且将學号自增1，用來賦給下一個建立的學生對象；
	}
	
	//計算每個學生的平均成績
	public double averScore(){
		return Math.round((computerScore + mathScore + englisdScore)/3);// 四舍五入
	}
	
	//計算每個學生的總成績
	public double sumScore(){
		return computerScore + mathScore + englisdScore;
	}
	
	//複寫toString()方法，用來輸出學生的資訊
	@Override
	public String toString() {
		return "Student [學号：" + num + ",姓名：" + name + ",年齡：" + age +
				",計算機成績：" + computerScore+ ",數學成績：" + mathScore + ",英語成績" + englisdScore + 
				"，各科平均成績：" + averScore() + ",各科總成績：" + sumScore() + "]";
	}

	//定義各私有成員變量的擷取方法和設定方法
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public int getAge() {
		return age;
	}
	public void setAge(int age) {
		this.age = age;
	}	
	public int getNum() {
		return num;
	}
	public void setNum(int num) {
		this.num = num;
	}
	public double getComputerScore() {
		return computerScore;
	}
	public void setComputerScore(double computerScore) {
		this.computerScore = computerScore;
	}
	public double getMathScore() {
		return mathScore;
	}
	public void setMathScore(double mathScore) {
		this.mathScore = mathScore;
	}
	public double getEnglisdScore() {
		return englisdScore;
	}
	public void setEnglisdScore(double englisdScore) {
		this.englisdScore = englisdScore;
	}
}
           

練習二：

package sonyi;
/*
	練習:
		定義一個表示雇員的類。屬性有：雇員編号，姓名，職位，月薪，獎金。
		要求雇員編号為類變量，每次增加成員時，編号自動增加，并指派給新增成員。計算雇員的月薪和年薪，列印雇員全部資訊。
		執行個體化幾個對象，并測試。
 */
public class EmployeeTest {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		//類的執行個體化，并賦初始值
		Employee e1 = new Employee("張三","前台",2000,500);
		Employee e2 = new Employee("小張","工程師",2000,500);
		Employee e3 = new Employee("小李","售後",2000,500);
		Employee e4 = new Employee("李四","前台",2000,500);
		Employee e5 = new Employee("王五","程式員",8000,1000);
		
		//列印類資訊
		System.out.println(e1);
		System.out.println(e2);
		System.out.println(e3);
		System.out.println(e4);
		System.out.println(e5);	
	}
}

class Employee{
	//靜态屬性，記錄新增成員編号，并指派給新增成員，指派後自加1
	private static int index = 1;
	private int no;//定義私有屬性
	private String name;
	private String position;
	private double salary;
	private double premium;
	
	Employee(){
		
	}
	
	//重載構造方法
	Employee(String name, String position,double salary,double premium){
		this.name = name;
		this.position = position;
		this.salary = salary;
		this.premium = premium;
		no = index++;
	}	
	
	
	//複寫toString，列印成員資訊
	@Override
	public String toString() {
		return "Employee [雇員編号：" + no + ", 姓名：" + name + ", 職位："
				+ position + ", 基本工資：" + salary + ", 獎金" + premium
				+ ", 月薪" + monthPay() + ", 年薪：" + annualPay() + "]";
	}
	
	//定義私有屬性的擷取方法和設定方法
	public double monthPay(){
		return salary + premium;
	}	
	public double annualPay(){
		return monthPay()*12;
	}
	
	//定義私有屬性的擷取方法和設定方法
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public int getNo() {
		return no;
	}
	public void setNo(int no) {
		this.no = no;
	}
	public String getPosition() {
		return position;
	}
	public void setPosition(String position) {
		this.position = position;
	}
	public double getSalary() {
		return salary;
	}
	public void setSalary(double salary) {
		this.salary = salary;
	}
	public double getPremium() {
		return premium;
	}
	public void setPremium(double premium) {
		this.premium = premium;
	}	
}