public static void main(String[] args) { // TODO Auto-generated method stub Scanner in=new Scanner(System.in); System.out.print("请输入第一个数:"); int num1=in.nextInt(); System.out.print("请输入第一个数:"); int num2=in.nextInt(); System.out.println("请选择算法:1.加2.减3.乘4.除"); int xz=in.nextInt(); switch(xz){ case 1: System.out.println("结果是:"+(num1+num2)); break; case 2: System.out.println("结果是:"+(num1-num2)); break; case 3: System.out.println("结果是:"+(num1*num2)); break; case 4: System.out.println("结果是:"+(num1/num2)); break; } } }本回答被提问者采纳
第2个回答 推荐于2017-12-19
如果需要进行 判断是否为数字 则需要加一段代码 import java.util.Scanner; public class Practive4 { public static void main(String[] args) { Scanner input = new Scanner(System.in); System.out.println("输入第一个数:"); if (input.hasNextInt() == true) { int a = input.nextInt(); System.out.println("输入第二个数:"); if (input.hasNextInt() == true) { int b = input.nextInt(); System.out.println("请输入你要的运算方法: 1.加 2.减 3.乘 4.除"); int option = input.nextInt(); switch (option) { case 1: System.out.println("a+b=" + (a + b)); break; case 2: System.out.println("a+b=" + (a - b)); break; case 3: System.out.println("a+b=" + (a * b)); break; case 4: System.out.println("a+b=" + (a / b)); break; default: System.out.println("误"); break; } } else { System.out.println("误"); return; } } else { System.out.println("误"); return; } } }本回答被网友采纳