综合案例讲解

案例

1、定义一个长方形类,定义求周长和面积的方法，然后定义一个测试类，进行测试。

public class anli {
    public static void main(String[] args) {
        Rectangle rectangle = new Rectangle(10,20);
        System.out.println("长方形周长："+rectangle.getPermeter());
        System.out.println("长方形面积："+rectangle.getArea());
    }
}
class Rectangle{
    private int length;
    private int width;

    /**
     * 周长
     */
    public int getPermeter(){
        return this.length*2+this.width*2;
    }
    /**
     * 面积
     */
    public int getArea(){
        return this.length*this.width;
    }

    public Rectangle() {
    }

    public Rectangle(int length, int width) {
        this.length = length;
        this.width = width;
    }

    public int getLength() {
        return length;
    }

    public void setLength(int length) {
        this.length = length;
    }

    public int getWidth() {
        return width;
    }

    public void setWidth(int width) {
        this.width = width;
    }
}

运行结果：

 

 

2、封装一个学生类，有姓名，有年龄，有性别，有英语成绩，数学成绩，语文成绩，封装方法，求总分，平均分，以及打印学生的信息。

package com.example.ObjectOriented.KeyWord;

public class anli2 {
    public static void main(String[] args) {
        Student student = new Student("张三",18,"男",89,45,36);
        student.show();
    }
}
class Student{
    private String name;
    private int age;
    private String gender;
    private double english;
    private double math;
    private double chinese;

    /**
     * 打印信息
     */
    public void show(){
        System.out.println("name="+"\t"+this.name+"\t age="+this.age+"\t gender="+this.gender
                +"\t english="+this.english+"\t math="+this.math+"\t chinese="+this.chinese);
    }
    /**
     * 总分
     */
    public double getSum(){
        return this.english+this.math+this.chinese;
    }

    /**
     * 平均分
     */
    public double avg(){
        return this.getSum()/3;
    }

    public Student() {
    }

    public Student(String name, int age, String gender, double english, double math, double chinese) {
        this.name = name;
        this.age = age;
        this.gender = gender;
        this.english = english;
        this.math = math;
        this.chinese = chinese;
    }

    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 String getGender() {
        return gender;
    }

    public void setGender(String gender) {
        this.gender = gender;
    }

    public double getEnglish() {
        return english;
    }

    public void setEnglish(double english) {
        this.english = english;
    }

    public double getMath() {
        return math;
    }

    public void setMath(double math) {
        this.math = math;
    }

    public double getChinese() {
        return chinese;
    }

    public void setChinese(double chinese) {
        this.chinese = chinese;
    }
}

public static void main(String[] args) {
    Student student = new Student("张三",18,"男",89,45,36);
    student.show();
    System.out.println(student.getSum());
    System.out.println(student.getAge());
}

 

运行结果：