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JavaScript JavaScript Foundations Variables Null and Undefined

Posted by keenan
keenan
6,764 Points

Need help with this challenge!

I don't know what to do with this challenge. I know the identical() method it's been called out to do what?

index.html 
<!DOCTYPE html>
<html lang="en">
  <head>
    <title> JavaScript Foundations: Variables</title>
    <style>
      html {
        background: #FAFAFA;
        font-family: sans-serif;
      }
    </style>
    <script src="ignore_this.js"></script>
  </head>
  <body>
    <h1>JavaScript Foundations</h1>
    <h2>Variables: Null and Undefined</h2>

    <div id="container">
    </div>

    <script>

        var myUndefinedVariable;
        var myNullVariable = null;

        if(myNullVariable == myUndefinedVariable) {
            identical(typeof myUndefinedVariable === "undefined");
        }

    </script>
  </body>
</html>

1 Answer

Colin Bell
Colin Bell
29,679 Points
Colin Bell
Colin Bell
29,679 Points

It's just asking that you use the strict equality operator. Try using === instead of == with the original code.

if (myNullVariable === myUndefinedVariable) {
    identical();
}

This is because:

null == undefined is true

null === undefined is false

And if you're looking for things to be identical, you don't want null and undefined to be equal.