Sort an array so that a given value would be the first

Question

I would like to sort the array so that if a given value ($first_in_array) = 'brand' value, the array would become the first it the queue. In the given example an array with index[1] should appear like at index[0].

$first_in_array = 'PickMeFirst';

$data = Array(
    0 => array(
        'articleId'     => 5478,
        'articleName'   => 'Demo artcle name 1',
        'brand'         => 'Unbranded',
       ),
    1 => array(
        'articleId'     => 8785,
        'articleName'   => 'Demo artcle name 2',
        'brand'         => 'PickMeFirst',
       ),
    2 => array(
        'articleId'     => 1258,
        'articleName'   => 'Demo artcle name 3',
        'brand'         => 'None',
       ),
);

Does this answer your question? [How can I sort arrays and data in PHP?](https://stackoverflow.com/questions/17364127/how-can-i-sort-arrays-and-data-in-php) — El_Vanja, May 02 '21 at 14:20
Look for `usort` examples. All you need to do is say that when the brand matches, that element should come before the other one. — El_Vanja, May 02 '21 at 14:22

Andrew Hardiman · Answer 1 · 2021-05-03T09:54:49.190

2

The accepted answer moves your value to the first position. However, it also moves other values. Which is absolutely fine, if that is not a concern for you. You could also do the following, which will move your value to the front, but leave other values in place.

usort($data, function ($a, $b) use ($first_in_array) {
    if($b['brand'] === $first_in_array) {
        return 1;
    } else {
        return 0;
    }
});

edited May 03 '21 at 09:54

answered May 02 '21 at 14:51

Andrew Hardiman

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1

It's not a problem in my case at the moment, but might me useful later on. I highly appreciate your addition to the solution. – Jurgen May 02 '21 at 15:08
1

Bear in mind that `strcmp` is case sensitive also. You can look into `strcasecmp` for a case-insensitive comparison. – Andrew Hardiman May 02 '21 at 15:10
1

Why not just test for `$b['brand'] === $first_in_array` instead of using `strcmp`? – Jeto May 02 '21 at 16:09
1

@Jeto no good reason that I can see, thank you for bringing that to my attention. – Andrew Hardiman May 03 '21 at 09:55

score 1 · Accepted Answer · answered May 02 '21 at 14:37

You can use the callback function of usort and first deal with the case where exactly one of the two matches that specific string. In all other cases use the normal strcmp result:

usort($data, function ($a, $b) use ($first_in_array)  {
    return ($b["brand"] === $first_in_array) - ($a["brand"] === $first_in_array)
        ?: strcmp($a["brand"], $b["brand"]);
});

Sort an array so that a given value would be the first

2 Answers2