Question

这是我到目前为止它不起作用我不知道为什么哈哈。我想我是以正确的方式做到了，但为什么

/*
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 * and open the template in the editor.
 */
package midterm;

import java.util.Scanner;

/**
 *
 * @author prvillanuevajr
 */
public class Calc {

    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        int x = 0;
        int y = 0;
        Myarithmetic m = new Myarithmetic();
        System.out.println("[1] - Add");
        System.out.println("[2] - Subtract");
        System.out.println("[3] - Multiply");
        System.out.println("[4] - Divide");
        System.out.print("CHOOSE: ");
        int choose = s.nextInt();
        switch (choose) {

            case 1:
                System.out.println("ADDITION");
                x = s.nextInt();
                y = s.nextInt();
                m.setX(x);
                m.setY(y);
                m.add();
                break;
            default:
                System.out.println("INVALID INPUT");
        }
    }
}

public class Myarithmetic {
    private int y;
    private int x;

    public int getY() {
        return y;
    }

    public void setY(int y) {
        this.y = y;
    }

    public int getX() {
        return x;
    }

    public void setX(int x) {
        this.x = x;
    }
    public int add(){
        int sum = 0;
        sum = getX()+getY();
        return sum;
    }
}

Answer 1

那是因为您在同一源文件中编写两个公共类删除public或将第二个文件写入新的.java文件

否则，我会在您的程序中向您显示一些修改，以便根据您的需要进行操作：

    public class A {
    public static void main(String args[]){
        Scanner sc= new Scanner(System.in);
        int x,y;
        System.out.println("1.add  2.subtract");
        System.out.println("Enter your choice: ");
        int choice = sc.nextInt();

        A obj = new A();
        switch(choice){
        case 1:
            System.out.println("Enter two number to add: ");
            x=sc.nextInt();
            y=sc.nextInt();
            obj.add(x,y);
            break;

        case 2:
            /*  Case 2 containts here   */
        }
    }

    public void add(int x, int y){
        int a=x,b=y;
        int answer = a+b;
        System.out.println("Addition is :"+answer);

    }
}

Answer 2

您实际上并未打印结果;你刚刚调用add()方法。

尝试：

System.out.println(m.add());

Java多类添加

2 个答案: