3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php function test() { $orderedids=array(7, 9, 5, 3); $tags=array( new Tag(3), new Tag(7), new Tag(5), new Tag(9) ); $flipped=array_flip($orderedids); return usort($tags, function($tag1, $tag2) { if ($flipped[$tag1->id]<$flipped[$tag2->id]) return -1; else if ($flipped[$tag1->id]==$flipped[$tag2->id]) return 0; else return 1; }); } class Tag { public $id; function __construct($id) { $this->id=$id; } } $rtags=test(); foreach ($rtags as $tag) echo $tag->id." ";
based on GqCGK
Output for 7.0.0 - 7.2.0
Notice: Undefined variable: flipped in /in/pDv7P on line 16 Notice: Undefined variable: flipped in /in/pDv7P on line 16 Notice: Undefined variable: flipped in /in/pDv7P on line 17 Notice: Undefined variable: flipped in /in/pDv7P on line 17 Notice: Undefined variable: flipped in /in/pDv7P on line 16 Notice: Undefined variable: flipped in /in/pDv7P on line 16 Notice: Undefined variable: flipped in /in/pDv7P on line 17 Notice: Undefined variable: flipped in /in/pDv7P on line 17 Notice: Undefined variable: flipped in /in/pDv7P on line 16 Notice: Undefined variable: flipped in /in/pDv7P on line 16 Notice: Undefined variable: flipped in /in/pDv7P on line 17 Notice: Undefined variable: flipped in /in/pDv7P on line 17 Warning: Invalid argument supplied for foreach() in /in/pDv7P on line 32
Output for 5.3.19 - 5.6.28
Notice: Undefined variable: flipped in /in/pDv7P on line 16 Notice: Undefined variable: flipped in /in/pDv7P on line 16 Notice: Undefined variable: flipped in /in/pDv7P on line 17 Notice: Undefined variable: flipped in /in/pDv7P on line 17 Notice: Undefined variable: flipped in /in/pDv7P on line 16 Notice: Undefined variable: flipped in /in/pDv7P on line 16 Notice: Undefined variable: flipped in /in/pDv7P on line 17 Notice: Undefined variable: flipped in /in/pDv7P on line 17 Notice: Undefined variable: flipped in /in/pDv7P on line 16 Notice: Undefined variable: flipped in /in/pDv7P on line 16 Notice: Undefined variable: flipped in /in/pDv7P on line 17 Notice: Undefined variable: flipped in /in/pDv7P on line 17 Notice: Undefined variable: flipped in /in/pDv7P on line 16 Notice: Undefined variable: flipped in /in/pDv7P on line 16 Notice: Undefined variable: flipped in /in/pDv7P on line 17 Notice: Undefined variable: flipped in /in/pDv7P on line 17 Warning: Invalid argument supplied for foreach() in /in/pDv7P on line 32