package com.company; 

import java.util.Scanner;  

public class Main {  

    while（true）
    {
    System.out.println("PLEASE INPUT TWO NUMBERS");
    Scanner scanner =new Scanner(System.in);
    Double a=scanner.nextDouble();
    Double b=scanner.nextDouble();

    System.out.println("PLEASE CHOOSE：1、ADD 2、MINUS 3、MULTIPLY 4、DIVIDE");
    int choice=scanner.nextInt();

    switch (choice) {
    case 1:
    System.out.print("结果为");
    System.out.println(a+b);
    break;
    case 2:
    System.out.print("结果为");
    System.out.println(a-b);
    break;
    case 3:
    System.out.print("结果为");
    System.out.println(a*b);
    break;
    case 4:
    if(b==0)System.out.println("ERROR");
    System.out.print("结果为");
    System.out.println(a/b);
    break;
    default:System.out.println("ERROR");
  }
}
}
}