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run code in 150+ php & hhvm versions
Bugs & Features
<?php define('R_MD5_MATCH', '/^[a-f0-9]{32}$/i'); if(preg_match(R_MD5_MATCH, $input_string)) { echo "It matches."; } else { echo "It does not match."; }
Output for 5.0.4 - 7.1.0
Notice: Undefined variable: input_string in /in/KLme1 on line 4 It does not match.
Output for 4.3.0 - 5.0.3
Notice: Undefined variable: input_string in /in/KLme1 on line 4 It does not match.