javaSE

package method;

import java.util.Scanner;

public class EnhancedTheCalculator {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        double res = 0;
        System.out.println("请输入第1个数字:");
        double num1 = scanner.nextDouble();
        System.out.println("请输入运算符:");
        String cal =scanner.next();
        System.out.println("请输入第二个数字:");
        double num2 = scanner.nextDouble();
        switch (cal) {
            case "+":
                res = num1 + num2;
                break;
            case "-":
                res = num1 - num2;
                break;
            case "*":
                res = num1 * num2;
                break;
            case "/":
                if (num2 != 0) {
                    System.out.println("运算结果为:\n" + num1 + cal + num2 + "=" + res);
                    break;
                } else {
                    System.out.println("结果不合法");
                    break;
                }
            default:
                System.out.println("土鸡你的运算符不合法，请稍后重试");
                return;
        }
                System.out.println("运算结果为:\n"+num1+cal+num2+"="+res);
                scanner.close();
        }
}

原文：https://www.cnblogs.com/luowuji262/p/15308005.html