java简单计算器

package com.zhang;

import java.nio.charset.StandardCharsets;
import java.util.Scanner;
import java.util.concurrent.CyclicBarrier;

public class calculator {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);

    System.out.println("请输入第一个数字：");
    double x = scanner.nextDouble();
    System.out.println("请选择方法（+.-.*./）：");
    char y = scanner.next().charAt(0);
    System.out.println("请输入第二个数字：");
    double z = scanner.nextDouble();
    System.out.println("结果为：");

    switch (y){
        case \'+\':
            double result_add = add(x,y,z);
            System.out.println(result_add);
            break;
        case  \'-\':
            double result_sub = sub(x,y,z);
            System.out.println(result_sub);
            break;
        case \'*\':
            double result_mul = mul(x,y,z);
            System.out.println(result_mul);
            break;
        case \'/\':
            double result_div = div(x,y,z);
            System.out.println(result_div);
            break;
    }
}
public static double add(double x,char y,double z){
    return x+z;
}
public static double sub(double x,char y,double z){
    return x-z;
}
public static double mul(double x,char y,double z){
    return x*z;
}
public static double div(double x,char y,double z){
    return (x/z);
}
}