3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php var_dump(substr('', 0, 0)); var_dump(substr('', 0, 1)); var_dump(substr('', 0, 2)); var_dump(substr('a', 0, 0)); var_dump(substr('a', 0, 1)); var_dump(substr('a', 0, 2)); var_dump(substr('ab', 0, 0)); var_dump(substr('ab', 0, 1)); var_dump(substr('ab', 0, 2));
Output for 7.0.0 - 7.1.0
string(0) "" string(0) "" string(0) "" string(0) "" string(1) "a" string(1) "a" string(0) "" string(1) "a" string(2) "ab"
Output for 4.3.0 - 5.6.28, hhvm-3.10.0 - 3.12.0
bool(false) bool(false) bool(false) string(0) "" string(1) "a" string(1) "a" string(0) "" string(1) "a" string(2) "ab"