3v4l.org

run code in 300+ PHP versions simultaneously
<?php class Foo { public function __construct($options = null) { if (is_array($options)) { var_dump(is_string(key($options))); } } } $options = array('foo' => 'bar'); next($options); next($options); $foo = new Foo($options);
Output for 7.0.0 - 7.0.33, 7.1.0 - 7.1.25, 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 - 8.1.29, 8.2.0 - 8.2.21, 8.3.0 - 8.3.9
bool(false)
Output for 5.6.0 - 5.6.38
bool(true)

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195.86 ms | 401 KiB | 262 Q