- array_column: documentation ( source)
- print_r: documentation ( source)
<?php
print_r(array_column(
array(
0 => array('test' => 1, 'test2' => 2),
1 => array('test' => 44, 'test2' => 22),
2 => array('test' => 51, 'test2' => 21),
), 'test'
));