Java基础系列（33）- 计算器

package method;

import java.util.Scanner;

public class Demo09 {
    static double result;
    static String ys = "运算符";
    static double num1=0;
    static double num2=0;

    public static void main(String[] args) {
        input();
        switch (ys){
            case "+":
                add(num1,num2);
                break;
            case "-":
                ajian(num1,num2);
                break;
            case "*":
                achen(num1,num2);
                break;
            case "\\":
                achu(num1,num2);
                break;
        }
        System.out.println(result);
    }

    public static void input(){


        Scanner scanner = new Scanner(System.in);
        System.out.print("输入第一个数字：");
        if (scanner.hasNext()){
            num1=scanner.nextDouble();
        }
        System.out.print("输入运算符：");
        if (scanner.hasNext()) {
            ys = scanner.next();
        }
        System.out.print("输入第二个数字：");
        if (scanner.hasNext()){
            num2=scanner.nextDouble();
        }
        scanner.close();
    }

    public static double add(double num1,double num2){
        result=num1+num2;
        return result;
    }
    public static double ajian(double num1,double num2){
        result=num1-num2;
        return result;
    }
    public static double achen(double num1,double num2){
        result=num1*num2;
        return result;
    }
    public static double achu(double num1,double num2){
        result=num1/num2;
        return result;
    }

}