3v4l.org

run code in 200+ PHP versions simultaneously
<?php $a1 = 'foo'; $1a = 'bar';
based on We2Uk
Output for 7.0.28 - 7.2.9
Parse error: syntax error, unexpected '1' (T_LNUMBER), expecting variable (T_VARIABLE) or '{' or '$' in /in/dVGQD on line 5
Process exited with code 255.
Output for 5.6.30
Parse error: syntax error, unexpected '1' (T_LNUMBER), expecting variable (T_VARIABLE) or '$' in /in/dVGQD on line 5
Process exited with code 255.