How to get unique value in multidimensional array

multidimensional-array, php, unique-values

Solution

Seems pretty simple: extract all `pid` values into their own array, run it through `array_unique`:

$uniquePids = array_unique(array_map(function ($i) { return $i['pid']; }, $holder));

The same thing in longhand:

$pids = array();
foreach ($holder as $h) {
    $pids[] = $h['pid'];
}
$uniquePids = array_unique($pids);

Problem

I have done a lot of looking around on the overflow, and on google, but none of the results works for my specific case. I have a placeholder array called $holder, values as follows: ``` Array ( [0] => Array ( [id] => 1 [pid] => 121 [uuid] => 1 ) [1] => Array ( [id] => 2 [pid] => 13 [uuid] => 1 ) [2] => Array ( [id] => 5 [pid] => 121 [uuid] => 1 ) ) ``` I am trying to pull out distinct/unique values from this multidimensional array. The end result I would like is either a variable containing (13,121), or (preferrably) an array as follows: Array( [0] => 13 [1] => 121 ) Again I've tried serializing and such, but don't quite understand how that works when operating with a single key in each array. I tried to be as clear as possible. I hope it makes sense...

Original source

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