3v4l.org

run code in 300+ PHP versions simultaneously
<?php $argument = "8BITMIME "; $verb = strtok( $argument, ' ' ); $arguments = substr( $argument, strlen( $verb ) + 1, strlen( $argument ) - strlen( $verb ) - 1 ); $_esmtp = array(); $_esmtp[$verb] = $arguments; var_dump($verb, $arguments, isset($_esmtp['8BITMIME'] ));
Output for 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
string(8) "8BITMIME" string(0) "" bool(true)
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
string(8) "8BITMIME" bool(false) bool(true)

preferences:
236.69 ms | 403 KiB | 342 Q