Question

我正在尝试编写经典的初学者代码，我在其中创建一个随机数，然后让用户尝试猜测它。我也尝试使用JOptionPane来获得一点想象力。一切正常，除了计算用户猜测随机数的次数的变量。它总是只有一个值低于应有的值（如果我在第三次尝试时得到它，它说我在两个中做到了正确）。我该如何解决？

第二个问题 - 我有out.println（randomNum）;在我要求用户猜测数字之前（所以我可以作弊），但是在我猜到一次之后它就不会在控制台中打印出来。那是怎么回事？任何帮助将不胜感激！

int randomNum = new Random().nextInt(11); //define random number
    int guess = Integer.parseInt(JOptionPane.showInputDialog("Guess a number from 1-10: "));
    int numGuesses = 1;
    out.println(randomNum); //cheater
    guess = Integer.parseInt(JOptionPane.showInputDialog("Guess a number from 1-10: "));
    while (guess != randomNum) {
        ++numGuesses; //to increase the value of numGuesses by 1 each time the while loop iterates

        guess = Integer.parseInt(JOptionPane.showInputDialog("Guess a number from 1-10: "));

     }
    JOptionPane.showMessageDialog(null, "You got it right after only " + numGuesses + " tries!");
    out.println(numGuesses); //To see if it matches the JOptionPane value

Answer 1

你真的很亲密！发生了什么事情是你在进入while循环之前进行两次猜测，而不是递增numGuesses。程序员经常试图避免重复代码。试试这个：

int randomNum = new Random().nextInt(11); //define random number
int guess = -1; // set it to an invalid value
int numGuesses = 0; // they haven't guessed at all at this point
out.println(randomNum); //cheater
while (guess != randomNum) {
    ++numGuesses; //to increase the value of numGuesses by 1 each time the while loop iterates

    guess = Integer.parseInt(JOptionPane.showInputDialog("Guess a number from 1-10: "));

 }
JOptionPane.showMessageDialog(null, "You got it right after only " + numGuesses + " tries!");
out.println(numGuesses); //To see if it matches the JOptionPane value

Answer 2

在您进入while循环之前，您甚至在检查猜测之前让用户猜两次。删除while循环前的第二个猜测：

int guess = Integer.parseInt(JOptionPane.showInputDialog("Guess a number from 1-10: "));
int numGuesses = 1;
System.out.println(randomNum); //cheater
// Remove the following line!
guess = Integer.parseInt(JOptionPane.showInputDialog("Guess a number from 1-10: "));

Answer 3

不要让用户两次询问随机值

guess = Integer.parseInt(JOptionPane.showInputDialog("Guess a number from 1-10: "));
while (guess != randomNum) {
    //...
    guess = Integer.parseInt(JOptionPane.showInputDialog("Guess a number from 1-10: "));

相反，请使用do-while循环，因为您希望它们至少猜一次......

int numGuesses = 0;
do {
    numGuesses++;
    guess = Integer.parseInt(JOptionPane.showInputDialog("Guess a number from 1-10: "));
} while (guess != random);

Answer 4

1）在进入while循环之前，您要求用户猜两次。由于numGuesses设置为1并且在进入while循环时加1，因此您将逐一关闭（您要求用户在while循环中第三次猜测该数字）。

2）由于您在提示用户猜测数字后打印“骗子”代码，因此只会在猜测后出现。

请注意 Random().nextInt(11)也包含0，因此您可能希望将guess初始化为-1，如下例所示：

    int randomNum = new Random().nextInt(11); //Define random number between 0 (inclusive) and 10 (inclusive)
    int guess = -1;
    int numGuesses = 0;

    out.println(randomNum); //Cheater

    while (guess != randomNum) {
        guess = Integer.parseInt(JOptionPane.showInputDialog("Guess a number from 0-10: "));
        numGuesses++; //To increase the value of numGuesses by 1 each time the while loop iterates
     }

    JOptionPane.showMessageDialog(null, "You got it right after only " + numGuesses + " tries!");
    out.println(numGuesses); //To see if it matches the JOptionPane value

愚蠢的初学者错误隐藏在某处

4 个答案: