3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php $string="___---_-username"; $1 = 'yay'; echo preg_replace('{([-_])\1+}', "$1", $string);
Output for 5.4.0 - 5.4.17
Parse error: syntax error, unexpected '1' (T_LNUMBER), expecting variable (T_VARIABLE) or '$' in /in/pYeCj on line 3
Process exited with code 255.
Output for 5.3.0 - 5.3.26
Parse error: syntax error, unexpected T_LNUMBER, expecting T_VARIABLE or '$' in /in/pYeCj on line 3
Process exited with code 255.