Java实现计算器功能+ - * /

public class calc {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入第一个数：");
        double x = scanner.nextDouble();
        System.out.println("请输入运算符：");
        String op = scanner.next();
        System.out.println("请输入第二个数：");
        double y = scanner.nextDouble();

        double result = calc(x,op,y);
        System.out.println(x+op+y+"="+result);
        scanner.close();
    }
    public static double calc(double x,String op,double y){
        double result = 0;
        switch (op){
            case "+":
                result = a(x,y);
                break;
            case "-":
                result = b(x,y);
                break;
            case "*":
                result = c(x,y);
                break;
            case "/":
                result = d(x,y);
                break;

        }
        return result;
    }



    public static double a(double x,double y){
        return x+y;
    }
    public static double b(double x,double y){
        return x-y;
    }
    public static double c(double x,double y){
        return x*y;
    }
    public static double d(double x,double y){
        return x/y;
    }
}