public class Demo6 {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
while (true){
System.out.println("请输入运行指令");
System.out.println("请输入第一个数：");
double num1 = scanner.nextDouble();
System.out.println("请输入运算符：");
String way = scanner.next();
System.out.println("请输入第二个数：");
double num2 = scanner.nextDouble();
Double result = 0.0;
switch (way) {
case "+":
result = num1 + num2;
break;
case "-":
result = num1 - num2;
break;
case "*":
result = num1 * num2;
break;
case "/":
result = num1 / num2;
break;
default:
System.out.println("输入有误！");
}
System.out.println(num1 + way + num2 + "=" + result);
}
}
}
