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run code in 200+ php & hhvm versions
Bugs & Features
<?php $value = 'a, moder php framework.= is a must 1234'; $output = preg_replace('/^[a-zA-z\d]/', '_', $value); echo $output;
based on VJjtZ
Output for 5.6.0 - 5.6.30, hhvm-3.15.4, 7.0.0 - 7.2.0
_, moder php framework.= is a must 1234