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

Posted by Sjoerd Vermeijden
Sjoerd Vermeijden
844 Points

While loop prompt untill correct answer

I have tried this in a alot of diffrent ways but can not get it to work.

It is the Javascript loops, Arrays > Simplify Repetitive Tasks with Loops > a closer look at loop conditions (2).

Can anyone help me?

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

while (secret === "sesame") 
     if (secret !== "sesame") {
        break;
    }
  }

document.write("You know the secret password. Welcome.");
index.html 
<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>JavaScript Loops</title>
</head>
<body>
<script src="app.js"></script>
</body>
</html>

4 Answers

Grace Kelly
Grace Kelly
33,990 Points
Grace Kelly
Grace Kelly
33,990 Points

Hi Sjoerd, you want to continue with the while loop as long as the password doesn't equal to "sesame", we do this in the following way:

var secret; 

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

As you can see the !== operator evaluates whether the password is equal to sesame, if it doesn't the user will be asked for the password again. To ask whether the password IS equal to "sesame" we place the following inside the while loop:

if (secret === "sesame") {
    break;
}

Notice the === operator? this asks if the password IS equal to "sesame" and if it is we want to break out of the loop.

Hope that helps!!

Sara Hardy
Sara Hardy
8,650 Points
Sara Hardy
Sara Hardy
8,650 Points

What you want to do is reverse this. While input is NOT equal to "sesame" prompt for password.

So first you'd just declare your variable without a value. Since it's empty, the first time your while loop hits, it will evaluate it as NOT equal to "sesame" and run the loop. Then inside that loop you call the prompt and set the value to your variable that is being checked. 

var secret;

while (secret !== "sesame") {
  secret = prompt("What is the secret password?");
}
Unsubscribed User
Unsubscribed User
6,144 Points
Unsubscribed User
Unsubscribed User
6,144 Points

Think about it, what do you really want to do ?

In a sentence, we could say : "while the answer from the visitor is not equal to 'sesame', keep prompting him".

Then you just have to translate this into code :)

Sjoerd Vermeijden
Sjoerd Vermeijden
844 Points

Thank!

Sjoerd Vermeijden
Sjoerd Vermeijden
844 Points
Sjoerd Vermeijden
Sjoerd Vermeijden
844 Points

Thank you!