url to clickable link

preg_replace.php

<!--
a few lines of code to make a url into a clickable link
using lazy star (.*?) and $0
-->
<?php
$string = 'http://www.haha.com www.haha.com hahahaha https://www.haha.com';
 
$string = $string." ";
 
$stringall = preg_replace('/((https:\/\/)|(http:\/\/)|(www\.))(.*?)(?=\s)/i','<a href="$0" target="_blank">$0</a>',$string);
 
$stringallc = preg_replace('/(href=\"www\.)/i','href="http://www.',$stringall);
 
echo $stringallc;
?>