3v4l.org

run code in 300+ PHP versions simultaneously
<?php $str = '1st blah blah <!-- CONTACT FORM START [CONTACT_FORM_1] -->some form goes here<!-- CONTACT FORM END 1 --> 2nd blah blah <!-- CONTACT FORM START [CONTACT_FORM_2] -->another form goes here<!-- CONTACT FORM END 2 -->'; $pattern = '/<!-- CONTACT FORM START \[CONTACT_FORM_(\d+)\] -->.*<!-- CONTACT FORM END \1 -->/'; $replace = preg_replace($pattern, '[CONTACT_FORM_$1]', $str); echo $replace;
Output for 5.6.0 - 5.6.40, 7.0.0 - 7.0.33, 7.1.0 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
1st blah blah [CONTACT_FORM_1] 2nd blah blah [CONTACT_FORM_2]
preferences:
207.82 ms | 403 KiB | 288 Q