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JavaScript JavaScript and the DOM (Retiring) Making Changes to the DOM DOM Manipulation

Posted by Alexandru Pescaru
Alexandru Pescaru
6,410 Points

who do i create a new class?

i'm a bit lost

app.js 
var contentDiv = document.getElementById('content');
var newParagraph = document.createElement('p');
index.html 
<!DOCTYPE html>
<html>
    <head>
        <title>DOM Manipulation</title>
    </head>
    <link rel="stylesheet" href="style.css" />
    <body>
        <div id="content">

        </div>
        <script src="app.js"></script>
    </body>
</html>

2 Answers

Jonathan Grieve
MOD
Jonathan Grieve
Treehouse Moderator 91,253 Points
Jonathan Grieve
Jonathan Grieve
Treehouse Moderator 91,253 Points

Hi there Alexandru,

This is about manipulating the DOM so you add a new class attribute that wasn't there before.

So, when you're working with the DOM you need to look at the HTML document tree, work out which element to select (that is to say what element to do something with and then perform an action on it.

In this challenge, we're selecting an element with the id of contact and you want to add a new paragraph element.

  • First create the paragraph element using DOM scripting with the method that makes a creates an element.
  • Secondly, in JavaScript you can use a property to set the class of an element, so the second task is about that.
  • Finally, creating the element doesn't add it to the DOM. To achieve this, you need to add the element as a child of the parent element.
Alexandru Pescaru
Alexandru Pescaru
6,410 Points
Alexandru Pescaru
Alexandru Pescaru
6,410 Points

but how to create in javaScript and set the class attribute

Jonathan Grieve
Jonathan Grieve
Treehouse Moderator 91,253 Points
Jonathan Grieve
Jonathan Grieve
Treehouse Moderator 91,253 Points

You need to use the className property. You can't use class as that is a reserved keyword in JavaScript. :-)

To create an element, that is to make it available to use in the DOM try the createElement() method and pass it the string of the element name you want to create which in this case is "p". Good luck! :-)