3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php function is_hex($hex_code) { return @preg_match("/^[a-f0-9]{2,}$/i", $hex_code) && !(strlen($hex_code) & 1); } var_dump(is_hex("A"));
Output for 4.3.0 - 5.6.28, hhvm-3.10.0 - 3.12.0, 7.0.0 - 7.1.0
bool(false)