java - 为什么我的代码不能多次随机生成？

Question

抱歉，这可能是一个新手问题，但我无法弄清楚这段代码有什么问题。我到处都找过了，但找不到任何答案。

问题是，当我需要随机生成 5 次时，它只会随机生成 num 和 num2 一次。非常感谢任何帮助。

import java.util.Scanner;

import java.util.Random;

public class Choice5
{
    public static void main(String [] args)
    {
        Random r = new Random();
        Scanner k = new Scanner(System.in);
        String name;

        int num= 1 + r.nextInt(10);
        int num2=1 + r.nextInt(10);

        int answer = num*num2;
        int attempt;
        int countcorrect = 0;
        int countincorrect =0;

        System.out.println("Hi, what's your name?");
        name =k.next();

        for(int x=1; x<=5; x++)
        {
            System.out.println("Test " +x+ " of 5");
                System.out.println("Ok " +name+ " What is " +num+ " x " +num2+ " ?");
                attempt = k.nextInt();

                if(attempt == answer)
                {
                    System.out.println("Good Job " +name+ " the answer was indeed " +answer);
                    countcorrect++;
                }
                if(attempt != answer)
                {
                    System.out.println("Incorrect " +name+ " the answer was actually " +answer);
                    countincorrect++;
                }
        }
                System.out.println("You got " +countcorrect+ " right");
                System.out.println("You got " +countincorrect+ " wrong");
                if (countcorrect < 3)
                {
                    System.out.println("You should try the test again");
                }
                else
                {
                    System.out.println("Good job " +name+ " ,you passed the test!");
                }

    }
}

Answer 1

您为 num 和 num2 选择随机数一次，位于 main 的顶部，更重要的是，在 >for 循环。这些数字不会再次分配，因此它们在所有循环迭代期间保持不变。

要让它们在每次循环迭代中发生变化，请声明数字和答案的变量，并在 for 循环内(而不是之前)分配新值。

for(int x=1; x<=5; x++)
{
    int num= 1 + r.nextInt(10);
    int num2=1 + r.nextInt(10);
    int answer = num*num2;
    // rest of code is the same