Short variable swap in PHP > 5.4.x

Following this great old post from David Walsh’s post Tweet for Code #2, here is a PHP adaptation for this JavaScript Var Swap tweet:

$b = [$a, $a = $b][0];

Works on PHP 5.4 and up.

I know this is not very practical, for daily work, but it can come handy in a job interview.

♦ ♦ ♦

[Update:June 16, 2016]

In PHP 7.1.x it will finally be possible to use a cleaner swap short-code:

[$a, $b] = [$b, $a];

[/Update]