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PHP: Search multidimensional array => get array_keys

What's the best/fastest way to get the keys of an array by a search of a value in the 2nd level arrays?

$test = array(
    'name_01' => array('yellow', 'red', 'blue', 'black', 'white', 'purple'),
    'name_02' => array('red', 'blue', 'white', 'green'),
    'name_03' => array('blue', 'pink', 'purple', 'blue'),
    'name_04' => array('white', 'black', 'red'),
    'name_05' => array('yellow', 'white', 'pink', 'black')
);

For example the search by pink should return array('name_03', 'name_05')

Solution

  • A simple foreach() with in_array() is enough

    $search = 'pink';

foreach($test as $key=>$arr){
   if(in_array($search,$arr)){
     echo $key.PHP_EOL;
   }

}

    Output : https://3v4l.org/HVem8

    If you want array as an output : https://3v4l.org/8e0sj