PHP function to get needed values form array

Question

function transformArray($array, $key)
{
  $transformed = [];
  foreach ($array as $k => $value) {
   $transformed[] = $value[$key]
 }
 return $transformed;
}

$array = [
0 => [
'key' => 1,
'key2' => 2
]
];

transformArray($array, 'key2');

Often I need function to build array from multidimesions array, for that I'm write function like in example, some frameworks have own function to do this, maybe for this solution exist shortest way with standart PHP functions ?

Missing semicolon(`;`) in `$transformed[] = $value[$key]`. From where you're getting this `$key`? — Rajdeep Paul, Jan 25 '16 at 18:40
**td;lr:** *you are looking for the best method to flatten a multidimensional array* — Rafael, Jan 25 '16 at 18:44
[Check this link](http://stackoverflow.com/questions/7994497/how-to-get-an-array-of-specific-key-in-multidimensional-array-without-looping) — pritesh, Jan 25 '16 at 18:46
@Wizard, I looked at your latest edit: you made it worse. The spelling should be the same for all occurrences of the variable. BTW, the English spelling is *transformed*. You can do it otherwise of course, but then do it consistently. — trincot, Jan 25 '16 at 18:48

score 2 · Accepted Answer · answered Jan 25 '16 at 18:45

Take a look to array_column function (supported since PHP 5.5).
It returns the values from a single column in the input multi-dimensional array.
Example from official documentation:

$records = array(
    array(
        'id' => 2135,
        'first_name' => 'John',
        'last_name' => 'Doe',
    ),
    array(
        'id' => 3245,
        'first_name' => 'Sally',
        'last_name' => 'Smith',
    ),
    array(
        'id' => 5342,
        'first_name' => 'Jane',
        'last_name' => 'Jones',
    ),
    array(
        'id' => 5623,
        'first_name' => 'Peter',
        'last_name' => 'Doe',
    )
);

$first_names = array_column($records, 'first_name');
print_r($first_names);

// output:
        Array
    (
        [0] => John
        [1] => Sally
        [2] => Jane
        [3] => Peter
    )

http://php.net/manual/ru/function.array-column.php

PHP function to get needed values form array

1 Answers1