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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 :)