HTML5 and CSS3, Video

CSS nth-child selector

In a couple of the previous tutorials we looked at child selectors and pseudo classes. In this tutorial, we will move on to the nth-child selector. The nth-child selector is used to select every element that is the nth child of a parent. For example, you could apply a style to every 2nd paragraph (every 2nd child) in a div. When using the nth-child selector, ‘n’ can be a number, a keyword or a formula.

In the example below we can change the colour of every 5th paragraph inside a div called ‘mydiv’. Because ‘n’ is 5, every 5th element will be selected.

#mydiv p:nth-child(5){
 color:red;
}

Here is an example of a keyword being used to apply a background-color style to odd paragraphs inside a div:

#mydiv p:nth-child(odd){
 background-color:green;
}

Watch the video below to see some of the different numbers, keywords, and formulas that can be used with the CSS nth-child selector. Then scroll down to see the sample code.

Here is the HTML sample code:

<!DOCTYPE html>
<html>
<head>
 <title>CSS nth-child() selector</title>
 <meta charset="utf-8"/>
 <link rel="stylesheet" href="resources/stylesheet11.css" type="text/css"/>
</head>
<body>
 <div id="mydiv">
 <p>The quick brown fox jumped over the lazy dog</p>
 <p>The quick brown fox jumped over the lazy dog</p>
 <p>The quick brown fox jumped over the lazy dog</p>
 <p>The quick brown fox jumped over the lazy dog</p>
 <p>The quick brown fox jumped over the lazy dog</p>
 <p>The quick brown fox jumped over the lazy dog</p>
 <p>The quick brown fox jumped over the lazy dog</p>
 <p>The quick brown fox jumped over the lazy dog</p>
 </div>
</body>
</html>

And here is the CSS code showing just the ‘even’ selection example from the video:

#mydiv p:nth-child(even){
 background-color:black;
 color:white;
}

Make sure you watch the video to see more examples of the numbers, keywords and formulas you can use with the nth-child selector. This video is also available here on my YouTube channel.