3v4l.org

run code in 300+ PHP versions simultaneously
<?php define('A', 1); define('B', 1); if(defined('A')) { function a() { echo "hello from `".__FUNCTION__."`\n"; } } if(defined('B')) { function b() { echo "hello from `".__FUNCTION__."`\n"; } } echo function_exists("b") ? "b is defined\n" : "b is not defined\n"; a(); echo function_exists("b") ? "b is defined\n" : "b is not defined\n"; b(); a(); echo function_exists("b") ? "b is defined\n" : "b is not defined\n";
Output for 4.3.0 - 4.3.11, 4.4.0 - 4.4.9, 5.0.0 - 5.0.5, 5.1.0 - 5.1.6, 5.2.0 - 5.2.17, 5.3.0 - 5.3.29, 5.4.0 - 5.4.45, 5.5.24 - 5.5.35, 5.6.8 - 5.6.28, 7.0.0 - 7.0.20, 7.1.0 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
b is defined hello from `a` b is defined hello from `b` hello from `a` b is defined
preferences:
247.86 ms | 405 KiB | 354 Q