Question

我编写了以下代码，询问“num1乘以num2多少钱？”的问题。但是，当我试图运行java文件时，我没有得到任何回应。能帮我理解我做错了吗？代码如下：

import java.util.Scanner;
import java.util.Random;

public class MultiplyLearn{

    public void Learn(){

        Random multiple = new Random();
        Scanner input = new Scanner( System.in );
        boolean wrong = true;

        int num1 = 1 + multiple.nextInt( 9 );
        int num2 = 1 + multiple.nextInt( 9 );

        while( wrong == true ){

        askQuestion( num1, num2 );
        int answer = input.nextInt();

        if( answer == num1*num2 ){
            System.out.println( "Very Good" );
            wrong = false;
        }

        else{
            System.out.print( "No. Please try again." );
        }
        }
    }

    public String askQuestion( int x, int y ){

        return "How much is" + x + "times" + y + "?";
    }
}

Answer 1

向您的班级添加主要方法

import java.util.Scanner;
import java.util.Random;

public class MultiplyLearn{

   //your actual code goes here

   public static void main(String args[]) throws Exception{
       new MultiplyLearn().Learn();
   }
}

所以你的最后一堂课看起来像

import java.util.Scanner;
import java.util.Random;

public class MultiplyLearn{

    public void Learn(){

        Random multiple = new Random();
        Scanner input = new Scanner( System.in );
        boolean wrong = true;

        int num1 = 1 + multiple.nextInt( 9 );
        int num2 = 1 + multiple.nextInt( 9 );

        while( wrong == true ){

        askQuestion( num1, num2 );
        int answer = input.nextInt();

        if( answer == num1*num2 ){
            System.out.println( "Very Good" );
            wrong = false;
        }

        else{
            System.out.print( "No. Please try again." );
        }
        }
    }

    public String askQuestion( int x, int y ){

        return "How much is" + x + "times" + y + "?";
    }

    public static void main(String args[]) throws Exception{
       new MultiplyLearn().Learn();
    }
}

Answer 2

import java.util.Random;
import java.util.Scanner;


public class MultiplyLearn {

    public static void main(String[] args) {
        // TODO Auto-generated method stub

        MultiplyLearn driver = new MultiplyLearn();
        //driver.askQuestion(2, 4);
        driver.Learn();

    }

    public void Learn(){

        Random multiple = new Random();
        Scanner input = new Scanner( System.in );
        boolean wrong = true;

        int num1 = 1 + multiple.nextInt( 9 );
        int num2 = 1 + multiple.nextInt( 9 );

        while( wrong == true ){

        // ISSUE: The returned value needs to be printed out. The program was waiting for input and hence it did not proceed from there(No O/P). I have corrected it.
        System.out.println(askQuestion( num1, num2 ));
        int answer = input.nextInt();

        if( answer == num1*num2 ){
            System.out.println( "Very Good" );
            wrong = false;
        }

        else{
            System.out.print( "No. Please try again." );
        }
        }
    }

    public String askQuestion( int x, int y ){

        return "How much is" + x + "times" + y + "?";
    }

}

Answer 3

我认为这就是你所需要的：

import java.util.Scanner;
import java.util.Random;

public class MultiplyLearn{

    public void learn(){

        Random multiple = new Random();
        Scanner input = new Scanner( System.in );
        boolean wrong = true;

        int num1 = 1 + multiple.nextInt( 9 );
        int num2 = 1 + multiple.nextInt( 9 );

        while(wrong){
            System.out.println("How much is " + num1 + " times " + num2 + "?");
            int answer = input.nextInt();

            if( answer == num1*num2 ){
                System.out.println( "Very Good" );
                wrong = false;
            }

        else{
            System.out.print( "No. Please try again." );
        }
        }
    }

    public static void main(String[] args)
    {
        MultiplyLearn learner = new MultiplyLearn();

        learner.Learn();
    }

几点：

命名约定建议方法应以小写字母开头
我没有看到单独提出问题的单独方法的重点

Answer 4

首先使用命名约定：http://java.about.com/od/javasyntax/a/nameconventions.htm 因此将Learn（）函数命名为learn（）。然后你必须从静态函数启动项目。因此，如果你想从learn（）函数启动项目，你需要使它成为静态（但在这种情况下你需要使其他函数也是静态的），或者如果你只想使用该函数，你需要编写一个静态主函数（在这种情况下优先）。

import java.util.Scanner;
import java.util.Random;

public class MultiplyLearn{

    public static void main(String args[]){
        MultiplyLearn multiplyLearn = new MultiplyLearn();
        multiplyLearn.learn();
    }

    public void learn(){

        Random multiple = new Random();
        Scanner input = new Scanner( System.in );
        boolean wrong = true;

        int num1 = 1 + multiple.nextInt( 9 );
        int num2 = 1 + multiple.nextInt( 9 );

        while( wrong == true ){

        askQuestion( num1, num2 );
        int answer = input.nextInt();

        if( answer == num1*num2 ){
            System.out.println( "Very Good" );
            wrong = false;
        }

        else{
            System.out.print( "No. Please try again." );
        }
        }
    }

    public String askQuestion( int x, int y ){

        return "How much is" + x + "times" + y + "?";
    }
}

使用随机整数询问乘法表

4 个答案: