Find youtube Link in PHP string and Convert it into embed code?

Try this:

preg_replace("/\s*[a-zA-Z\/\/:\.]*youtube.com\/watch\?v=([a-zA-Z0-9\-_]+)([a-zA-Z0-9\/\*\-\_\?\&\;\%\=\.]*)/i","<iframe width=\"420\" height=\"315\" src=\"//www.youtube.com/embed/$1\" frameborder=\"0\" allowfullscreen></iframe>",$post_details['description']);

A little enhancement of Joran's solution to handle also youtube short URL format:

function convertYoutube($string) {    return preg_replace(        "/\s*[a-zA-Z\/\/:\.]*youtu(be.com\/watch\?v=|.be\/)([a-zA-Z0-9\-_]+)([a-zA-Z0-9\/\*\-\_\?\&\;\%\=\.]*)/i",        "<iframe src=\"//www.youtube.com/embed/$2\" allowfullscreen></iframe>",        $string    );}

You can test this function online here

There are two types of youtube link for one video:

Example:

$link1 = 'https://www.youtube.com/watch?v=NVcpJZJ60Ao';$link2 = 'https://www.youtu.be/NVcpJZJ60Ao';

This function handles both:

function getYoutubeEmbedUrl($url){     $shortUrlRegex = '/youtu.be\/([a-zA-Z0-9_-]+)\??/i';     $longUrlRegex = '/youtube.com\/((?:embed)|(?:watch))((?:\?v\=)|(?:\/))([a-zA-Z0-9_-]+)/i';    if (preg_match($longUrlRegex, $url, $matches)) {        $youtube_id = $matches[count($matches) - 1];    }    if (preg_match($shortUrlRegex, $url, $matches)) {        $youtube_id = $matches[count($matches) - 1];    }    return 'https://www.youtube.com/embed/' . $youtube_id ;}

The output of $link1 or $link2 would be the same :

 $output1 = getYoutubeEmbedUrl($link1); $output2 = getYoutubeEmbedUrl($link2); // output for both:  https://www.youtube.com/embed/NVcpJZJ60Ao

Now you can use the output in iframe!