Remove from 2d array if it belongs in array

Question

I'm trying to remove arrays in the cars array if the make value belongs in the retiredCars array. I did run into array_search but I'm not sure how to apply it to a multi dimensional array

$retiredCars = array("Saab", "Saturn", "Pontiac");

$cars = array
  (
  array('make' => 'BMW', 'model' => '325'),
  array('make' => 'Saab', 'model' => '93'),
  array('make' => 'Pontiac', 'model' => 'GTO')
  );

In the example above, the $cars array should only contain the 'BMW' array after processing

for loop with in_array, for example – splash58 May 10 '17 at 08:39 — splash58, May 10 '17 at 08:39
Refer this http://stackoverflow.com/a/43830016/6521116 – LF00 May 10 '17 at 09:04 — LF00, May 10 '17 at 09:04

score 1 · Accepted Answer · answered May 10 '17 at 08:42

1

foreach ($cars as $key => $arr) {
    if (in_array($arr['make'], $retiredCars))
        unset($cars[$key]);
}

answered May 10 '17 at 08:42

ES112

91
4

1

Hi, code-only answers might solve the problem, but they are way less valuable to further readers, than an answer, that also contains some explaination. Therefore it would be highly appreciated, if you could expand your answer to include some explaination. – derM - not here for BOT dreams May 10 '17 at 11:13

KotBehemot · Answer 2 · 2017-05-10T08:52:55.173

0

Unsetting array's elements while iterating over it doesn't seem a good approach. Another idea:

$array_elem_passes = function ($val) use ($retiredCars)
{
        if (in_array($val['make'], $retiredCars))
                return false;

        return true;
};

$ret = array_filter($cars, $array_elem_passes);

edited May 10 '17 at 08:52

answered May 10 '17 at 08:45

KotBehemot

111
8

It looks like the perfect approach to me in this case. Your way will be much slower. Can you explain why you think differently? – ES112 May 13 '17 at 12:43
I think that, as a general rule, modifying an array while you're iterating on it isn't something that should be encouraged as it potentially can cause unwanted behaviour. – KotBehemot May 15 '17 at 08:43

score 0 · Answer 3 · edited May 23 '17 at 12:26

You can use array_filter, for performance flip the retiredCars array. Live demo

You also can use array_udiff to make it. Refer to this post.

<?php
$retiredCars = array("Saab", "Saturn", "Pontiac");

$cars = array
  (
  array('make' => 'BMW', 'model' => '325'),
  array('make' => 'Saab', 'model' => '93'),
  array('make' => 'Pontiac', 'model' => 'GTO')
  );

$makes = array_flip(array_unique($retiredCars));
print_r(array_filter($cars, function($v)use($makes){return isset($makes[$v['make']]);}));

score 0 · Answer 4 · answered May 10 '17 at 09:18

Yes. array_udiff do the trick in this way

$res = array_udiff($cars, $retiredCars, 
     function($c, $r) { 
         // You need test both variable because udiff function compare them in all combinations
         $a = is_array($c) ? $c['make'] : $c;
         $b = is_array($r) ? $r['make'] : $r;
         return strcmp($a, $b); 
         });

print_r($res);

demo on eval.in

Remove from 2d array if it belongs in array

4 Answers4