Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

JavaScript JavaScript Quickstart Functions Write a Function

What is a parameter?

I need help

script.js
function add10() {
  var num="0";
}
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="script.js"></script>
</body>
</html>

2 Answers

Steven Parker
Steven Parker
231,269 Points

A parameter is a placeholder for a value that will be given (known as "passing") to the function. Parameters have names like variables (such as "num" in this case), and are put between the parentheses after the function name on the first line. When you have more than one (not the case here), the names are separated by commas.

The variable name that goes in between the parenthesis. In this case they want you to put 'num' in between the parenthesis.