Question

How can I check if the values are unique in an array based on the key value? Below is the out put of the array. I want to remove duplicate values based on the “id” key. If you check below, the 2nd & 3rd array are same except for the “role” value. Because of this, array_unique is not working on this array.

array
  0 => 
    array
      'id' => string '1521422' (length=7)
      'name' => string 'David Alvarado' (length=14)
      'role' => string 'associate producer  ' (length=20)
  1 => 
    array
      'id' => string '0098210' (length=7)
      'name' => string 'Cristian Bostanescu' (length=19)
      'role' => string 'line producer: Romania  (as Cristi Bostanescu)' (length=46)
  2 => 
    array
      'id' => string '1266015' (length=7)
      'name' => string 'Bruno Hoefler' (length=13)
      'role' => string 'co-producer  ' (length=13)
  3 => 
    array
      'id' => string '1266015' (length=7)
      'name' => string 'Bruno Hoefler' (length=13)
      'role' => string 'executive producer  ' (length=20)
  4 => 
    array
      'id' => string '1672379' (length=7)
      'name' => string 'Alwyn Kushner' (length=13)
      'role' => string 'associate producer  ' (length=20)

Answer 1

Try this one:

<?php
$array = array(
    array('id' => 1, 'text' => 'a'),
    array('id' => 2, 'text' => 'b'),
    array('id' => 1, 'text' => 'c'),
    array('id' => 3, 'text' => 'd')
);
$array = array_filter($array, function ($item) {
    static $found = array();
    if (isset($found[$item['id']])) return false;
    $found[$item['id']] = true;
    return true;
});

var_dump($array);

This works as of PHP 5.3 (because of the closure and static statement).

cf. http://php.net/manual/en/function.array-filter.php for more information. I tested the statement within loops, it works there as well.