Welcome to the Treehouse Community

The Treehouse Community is a meeting place for developers, designers, and programmers of all backgrounds and skill levels to get support. Collaborate here on code errors or bugs that you need feedback on, or asking for an extra set of eyes on your latest project. Join thousands of Treehouse students and alumni in the community today. (Note: Only Treehouse students can comment or ask questions, but non-students are welcome to browse our conversations.)

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and a supportive community. Start your free trial today.

JavaScript JavaScript Loops, Arrays and Objects Simplify Repetitive Tasks with Loops A Closer Look At Loop Conditions

Christiaan Quyn
Christiaan Quyn
14,706 Points

Why can't I set a Variable inside a while loop ?

So I got the challenge right, I'm just a little confused as to why I cant assign var to secret in the while loop, I just happened to take it off and passed the challenge but I'd love if someone could explain to me why I can't do this ? So a variable shouldn't be set in the loop ? By taking var out what does that exactly do ?

Cheers :D

var secret = prompt("What is the secret password?");

while (secret !== "sesame") {
  secret = prompt("What is the secret password?");
}

document.write("You know the secret password. Welcome.");

1 Answer

Daniel Gauthier
Daniel Gauthier
15,000 Points

Hey Christiaan,

I'm assuming that the question you're asking is that you tried this code:

var secret = prompt("What is the secret password?");

while (secret !== "sesame") {
  var secret = prompt("What is the secret password?");
}

document.write("You know the secret password. Welcome.");

& you're wondering why you couldn't use the var keyword in the loop?

If so, the explanation is that you only use the var keyword when you first create the variable.

Since you had already created the variable outside of the loop, you can then set the variable using the assignment operator (the equals sign).

The var keywords simply tells the parser "I'd like to create a new variable", so variables that have already been created can skip this part.

So, the reason the code above didn't pass is because you were telling the parser "I'd like to create a variable named secret." when one had already been created using that name.

For the record, the code would work in a real world application the way you tried it, but it's not the best practice.

Good luck with the course!

Christiaan Quyn
Christiaan Quyn
14,706 Points

Oh .. I get it now .. thank you so much :)