Java新手入门练习题

用Java编写一个简易计算器

用四个方法：加减乘除

利用循环swich与用户进行交互

传递两个数

输出结果

代码如下：

package com.kuang.struct;

import java.util.Scanner;

public class JiSuanDemon {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        while (true){
            System.out.println("请输入y开始计算，输入n则退出程序");
            String a = scanner.next();

            if (a.equals("y")){
                System.out.println("请输入第一个数：");
                float num1 = scanner.nextFloat();

                System.out.println("请输入运算符：");
                String operator = scanner.next();

                System.out.println("请输入第二个数：");
                float num2 = scanner.nextFloat();

                switch (operator){
                    case "+":
                        add(num1,num2);
                        break;
                    case "-":
                        substract(num1,num2);
                        break;
                    case "*":
                        multiply(num1,num2);
                        break;
                    case "/":
                        divide(num1,num2);
                        break;
                }

            }else {
                System.out.println("退出");
                break;
            }

        }
        scanner.close();

    }

    public static void add(float a,float b){
        System.out.println("a+b="+(a+b));
    }
    public static void substract(float a,float b){
        System.out.println("a-b="+(a-b));
    }
    public static void multiply(float a,float b){
        System.out.println("a*b="+(a*b));
    }
    public static void divide(float a,float b){
        System.out.println("a/b="+(a/b));
    }
}