Question

I feel really stupid right now since I can remember doing something like this. But now my head is empty and this really seems to look like a problem.

I have two arrays. First:

array (
  0 => 
  array (
    'id' => '1',
    'name' => 'Blizzard',
    'slug' => 'blizzard',
  ),
  1 => 
  array (
    'id' => '2',
    'name' => 'Id Software',
    'slug' => 'id-software',
  ),
  2 => 
  array (
    'id' => '3',
    'name' => 'Capcom',
    'slug' => 'capcom',
  ),
  3 => 
  array (
    'id' => '4',
    'name' => 'Maxis',
    'slug' => 'maxis',
  ),
  4 => 
  array (
    'id' => '5',
    'name' => 'Electronic Arts',
    'slug' => 'electronic-arts',
  ),
)

And secound one:

array (
  0 => '3',
  1 => '4',
)

What I want to do is, take value from the secound array and match it with the value of the first one. How can I do this?

Answer 1

When you say “by value”, I’m assuming you meant by id value, in which case, if you already know that the id value is one less than the key, you can do this:

foreach( $second as $id) {
    $key = $id - 1;
    $row = $first[ $key ];
    echo $row['name'];
}

Otherwise, you’ll have to loop / search for the specific id:

foreach( $second as $id) {
    foreach( $first as $row) {
         if( $row['id'] == $id) {
              echo $row['name']; break;
         }
    }        
}

However, another trick you can use to just get an array containing the elements you want is to use array_filter(), like so:

$second = array( 3, 4);
$keep = array_filter( $first, function( $el) use( $second) { 
    return in_array( $el['id'], $second); 
}); 

Now $keep will contain an array of the two values you want, and you can loop over them accordingly.