codeacademy if/else javascript

Question

我正在学习JS的CodeAcademy课程，但是有一个问题，脚本是有效的，但是我

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console.log("You are at a Justin Bieber concert, and you hear this lyric 'Lace my shoes off, start racing.'");
console.log("Suddenly, Bieber stops and says, 'Who wants to race me?'");
var userAnswer = prompt("Do you want to race Bieber on stage?");

if(userAnswer === "yes") {
    console.log("You and Bieber start racing. It's neck and neck! You win by a shoelace!");
}
else {
    console.log("Oh no! Bieber shakes his head and sings 'I set a pace, so I can race without pacing.'");
}

​

给我错误信息：

Oops, try again. Did you add an if statement to your code?

在这里页面：https://www.codecademy.com/courses/javascript-beginner-en-x9DnD/0/5?curriculum_id=506324b3a7dffd00020bf661，它在你自己的冒险代码中！5.

Answer 1

我猜它可能是Codeacadamey的一个bug。奇怪的是，下面的代码正常工作，并给我一个绿色的图标。

编写if、else if和else语句可以解决这些问题。这可能是因为说明不是很清楚。

// Check if the user is ready to play!
var userAnswer = prompt("Do you want to race Bieber on stage?");

if (userAnswer === 'yes') {
    console.log("You and Bieber start racing. It's neck and neck! You win by a shoelace!");
} else if (userAnswer === 'no') {
    console.log("Oh no! Bieber shakes his head and sings 'I set a pace, so I can race without pacing.'");
} else {
    console.log("Oh no! Bieber shakes his head and sings 'I set a pace, so I can race without pacing.'");
}

Answer 2

您的代码可以在浏览器中运行，我可以在浏览器控制台窗口中看到结果，所以我认为您应该将此报告为bug。

但是，您只需要检查小写的yes。Yes或YES将与if语句不匹配，并将运行else块中的代码。

您可以尝试：

if(userAnswer.toLowerCase() === "yes") {    
    // Your code here
} else {
    // Your code here
}

Answer 3

有时，Codeacademy会根据微不足道的空格差异错误地报告代码中的错误。根据脚本的输出，您已经正确地编写了代码。

有趣的是，使用ternary operator而不是if语句可以很好地工作：

// Check if the user is ready to play!

console.log("You are at a Justin Bieber concert, and you hear this lyric 'Lace my shoes off, start racing.'");
console.log("Suddenly, Bieber stops and says, 'Who wants to race me?'");
var userAnswer = prompt("Do you want to race Bieber on stage?");

console.log( userAnswer === "yes" ?
    "You and Bieber start racing. It's neck and neck! You win by a shoelace!" :
    "Oh no! Bieber shakes his head and sings 'I set a pace, so I can race without pacing.'"
);