3v4l.org

run code in 300+ PHP versions simultaneously
<?php class Foo { function __construct() { $this->bar = new Bar($this); } } class Bar { function __construct($foo = null) { $this->foo = $foo; } } $i = 1; while ($i > 1000) { $foo = new Foo(); unset($foo); echo number_format(memory_get_usage()) . "\n"; $i++; }
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 - 7.1.7, 7.2.0

preferences:
135.43 ms | 404 KiB | 175 Q