除了第二个 else-if 语句外，所有条件都有效，如何纠正此问题？-解网

问：

我正在学习 Java，我不知道是什么让我的代码无法读取我的 else-if 条件（i == 5）

int i;    
for (i = 1; i <= 5; i++) {
    int guess = scanner.nextInt();
    System.out.println("Attempt: " + i +"/5");
    if (guess < numberToGuess) {
        System.out.println("Higher");
    } else if (guess > numberToGuess) {
            System.out.println("Lower");
    } else if (i == 5) {
        System.out.println("You failed! The correct answer is " + numberToGuess);
    } else {
        System.out.println("You won! Your answer is " + numberToGuess + " which is correct!");
        break;
    }

当我运行代码并尝试通过达到 int i 的最大数量（即 5）来使游戏失败时，应该出现第二个 else if 语句，但它不起作用。

我只是不明白它没有读取（i==5）条件的原因，除此之外所有其他条件都在工作。

java if 语句相等

if (guess < numberToGuess) {
    System.out.println("Higher");
} else if (guess > numberToGuess) {
    System.out.println("Lower");
} else if (i == 5) {
    System.out.println("You failed! The correct answer is " + numberToGuess);
} else {
    System.out.println("You won! Your answer is " + numberToGuess + " which is correct!");
    break;
}

即使，如果满足或中的任何一个，其余的语句 including 也会被忽略。i == 5guess < numberToGuessguess > numberToGuess(i == 5)

要解决此问题，只需添加为要检查的第一个条件，因为如果满足，我们无论如何都不应该考虑猜测。i == 5i == 5

我还猜如果游戏结束，你想打破循环，所以我也添加了一个声明。break

if (i == 5) {
    System.out.println("You failed! The correct answer is " + numberToGuess);
    break;
} else if (guess < numberToGuess) {
    System.out.println("Higher");
} else if (guess > numberToGuess) {
    System.out.println("Lower");
}  else {
    System.out.println("You won! Your answer is " + numberToGuess + " which is correct!");
    break;
}

0赞 kboskin 6/13/2022 #2

所以，看起来是这样，因为在检查你是否处于正确的循环条件下之前，有变量的检查

... 
if (guess < numberToGuess) {
            System.out.println("Higher");
        } else if (guess > numberToGuess) {
                System.out.println("Lower");
        } 
....

哪些被执行。因此，要修复该错误，只需将检查 i == 5 移动到第一个分支子句即可。代码应如下所示

if (i == 5) {
    System.out.println("You failed! The correct answer is " + numberToGuess);
} else if (guess > numberToGuess) {
    System.out.println("Lower");
} else if (guess < numberToGuess) {
     System.out.println("Higher");
} else {
    System.out.println("You won! Your answer is " + numberToGuess + " which is correct!");
    break;
}

这样，您可以先检查循环条件，然后检查输入条件

0赞 azro 6/13/2022 #3

这就是工作原理，您的值将低于或高于猜测值，因此第一个 2 个条件的一个为真，然后不会检查其他条件if/else if/else

首先设置停止条件

int nb_tries = 5;
for (i = 1; i <= nb_tries; i++) {
    System.out.print("Attempt: " + i + "/" + nb_tries + " => ");
    int guess = scanner.nextInt();

    if (i == nb_tries) {
        System.out.println("You failed! The correct answer is " + numberToGuess);
    } else if (guess < numberToGuess) {
        System.out.println("Higher");
    } else if (guess > numberToGuess) {
        System.out.println("Lower");
    } else {
        System.out.println("You won! Your answer is " + numberToGuess + " which is correct!");
        break;
    }
}

0赞 user2016942 6/13/2022 #4

使用 if-else 语句时的经验法则是 which ever 条件将满足到最早，它将进入该声明并之后，它将在 if-else 条件之外执行代码。

所以在你的情况下，if-else 语句的工作方式是这样的：当任何一个的语句被满足，其余的语句被忽略。拿以你的为例。

if (guess < numberToGuess) {
     System.out.println("Higher"); } else if (guess > numberToGuess) {
     System.out.println("Lower"); } else if (i == 5) {
     System.out.println("You failed! The correct answer is " + numberToGuess); } else {
     System.out.println("You won! Your answer is " + numberToGuess + " which is correct!");
    break; }

即使 i == 5，如果 guess < numberToGuess 或 guess > numberToGuess 满足，它将执行其中任何一个，而不是 i==5。因此，只要想想您想要赋予更多优先级的逻辑。

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除了第二个 else-if 语句外，所有条件都有效，如何纠正此问题？

all of the condition are working except on the second else-if statement, how to correct this?

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