3v4l.org

run code in 300+ PHP versions simultaneously
<?php // Concat $a = 'Hello '; $b = 'World!'; $out = $a . $b; echo $out; $out2 = printf("%s%s", $a, $b); echo $out2;
Output for 4.3.7 - 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 - 8.3.7
Hello World!Hello World!12
Output for 4.3.0 - 4.3.6
Hello World!Hello World!
preferences:
234.59 ms | 401 KiB | 341 Q