3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php echo trim(substr($discount_matrix, 0, 1));
Output for 5.0.4 - 7.1.0
Notice: Undefined variable: discount_matrix in /in/i3860 on line 2
Output for 4.3.0 - 5.0.3
Notice: Undefined variable: discount_matrix in /in/i3860 on line 2