Slicing a multi-dimensional PHP array across one of its elements

Question

Say for example you just queried a database and you recieved this 2D array.

$results = array(
    array('id' => 1, 'name' => 'red'  , 'spin' =>  1),
    array('id' => 2, 'name' => 'green', 'spin' => -1),
    array('id' => 3, 'name' => 'blue' , 'spin' => .5)
);

I often find myself writing loops like this.

foreach($results as $result)
    $names[] = $result['name'];

My questions is does there exist a way to get this array $names without using a loop? Using callback functions count as using a loop.

Here is a more generic example of getting every field.

foreach($results as $result)
    foreach($result as $key => $value)
        $fields[$key][] = $value;

Answer 1

As of June 20th in PHP-5.5 there is a new function array_column

For example:

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

Will return

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

There are even more examples in the above mentioned link.

Answer 2

I voted @Devon's response up because there really isn't a way to do what you're asking with a built-in function. The best you can do is write your own:

function array_column($array, $column)
{
    $ret = array();
    foreach ($array as $row) $ret[] = $row[$column];
    return $ret;
}

Answer 3

Starting PHP 5.3, you can use this pretty call with lambda function:

$names = array_map(function ($v){ return $v['name']; }, $results);

This will return array sliced by 'name' dimension.