3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php var_dump(preg_replace('#(http|https):\/\/([.a-zA-Z0-9]*)mailjet\.([\S]*)#', '//$2mailjet.$3', 'http://test.mailjet.com/?url=http://example.mailjet.com'));
Output for 5.6.38 - 7.3.0rc3
string(50) "//test.mailjet.com/?url=http://example.mailjet.com"