[Java知识库]java练习题-计算器

4、编写Java程序模拟简单的计算器。
定义名为Number的类其中有两个整型数据成员n1和n2应声明为私有。
编写构造方法赋予n1和n2初始值
再为该类定义加addition()、减substation()、乘multiplication()、除division()等公有实例方法
分别对两个成员变量执行加、减、乘、除的运算。
在main方法中创建Number类的对象调用各个方法并显示计算结果

public class HomeWork4 {
    //在main方法中创建Number类的对象调用各个方法并显示计算结果
    public static void main(String[] args) {
        Number n1 = new Number(20,30);
        System.out.println("两个数字分别是：" + n1.getN1() + "和" + n1.getN2());
        n1.addition();
        n1.substation();
        n1.multiplication();
        n1.division();

        //测试特殊情况 n2为0时 无法作为除数
        Number n2 = new Number(20,0);
        System.out.println("两个数字分别是：" + n2.getN1() + "和" + n2.getN2());
        n2.addition();
        n2.substation();
        n2.multiplication();
        n2.division();
    }
}

class Number {
    //私有变量n1、n2
    private double n1;
    private double n2;

    //构造方法
    public Number() {
    }

    public Number(double n1, double n2) {
        this.n1 = n1;
        this.n2 = n2;
    }

    //getting and setting


    public double getN1() {
        return n1;
    }

    public void setN1(double n1) {
        this.n1 = n1;
    }

    public double getN2() {
        return n2;
    }

    public void setN2(double n2) {
        this.n2 = n2;
    }

    //加
    public void addition() {
        System.out.println(this.getN1() + "+" + this.getN2() + "=" + this.getN1()+this.getN2());
    }

    //减
    public void substation() {
        double result = this.getN1()-this.getN2();
        System.out.println(this.getN1() + "-" + this.getN2() + "=" + result);
    }

    //乘
    public void multiplication() {
        System.out.println(this.getN1() + "*" + this.getN2() + "=" + this.getN1()*this.getN2());
    }

    //除
    public void division() {
        if(n2 == 0){
            System.out.println("除数不能为0！");
            return;
        }else
            System.out.println(this.getN1() + "/" + this.getN2() + "=" + this.getN1()/this.getN2());
    }
}