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JavaScript JavaScript Basics (Retired) Storing and Tracking Information with Variables Using String Methods

Daniel Glennie
Daniel Glennie
42,854 Points

Why won't this concatenation work? I have tried += and x + y + z formatting.

I have created a variable called userName and assigned the output of toUpperCase(id). I have tried to add the # and SMITH like this

var userName = String.prototype.toUpperCase(id) + "#" + String.prototype.toUpperCase(lastName);

and like this var userName = String.prototype.toUpperCase(id); userName += "#"; userName += String.prototype.toUpperCase(lastName);

What am I missing?

app.js
var id = "23188xtr";
var lastName = "Smith";

var userName = String.prototype.toUpperCase(id);
userName += "#"; 
userName =+ String.prototype.toUpperCase(lastName);
index.html
<!DOCTYPE HTML>
<html>
<head>
  <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
  <title>JavaScript Basics</title>
</head>
<body>
<script src="app.js"></script>
</body>
</html>

1 Answer

Jennifer Nordell
seal-mask
STAFF
.a{fill-rule:evenodd;}techdegree
Jennifer Nordell
Treehouse Teacher

Hi there! In your last line, you have the + and equals signs backwards. It should be +=. But even if I change that, the challenge still fails. You ned to run the toUpperCase method directly on the string in question.

var userName = id.toUpperCase() + "#" + lastName.toUpperCase();

Hope this helps! :sparkles:

edited for accuracy and additional information

Here's the MDN documentation:

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/toUpperCase

Daniel Glennie
Daniel Glennie
42,854 Points

Thank you! I noticed the += was the wrong way round right as soon as I posted the question but that didn't fix the problem. It seemed as if the final value assigned to userName was just "#" but I can't think why that would be.