php - Swap my element's order to be the first in an array -

let's have array so:

array(   [0]=>1   [1]=>3   [3]=>5   [15]=>6 );

arbitrarily want array[15] first:

array(   [15]=>6   [0]=>1   [1]=>3   [3]=>5 );

what fastest , painless way this?

here things i've tried:

array_unshift - unfortunately, keys numeric , need keep order (sort of uasort) messes keys.

uasort - seems overhead - reason want make element first in array avoid uasort! (swapping elements on fly instead of sorting when need them)

you can try this using slice , union operator:

// last element (preserving keys) $last = array_slice($array, -1, 1, true);  // put union operator $array = $last + $array;

update: as mentioned below, answer takes last key , puts @ front. if want arbitrarily move element front:

$array = array($your_desired_key => $array[$your_desired_key]) + $array;

union operators take right , add left (so original value gets overwritten).

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