array_diff_ukey

Computes the difference of arrays using a callback function on the keys for comparison (PHP 5 >= 5.1.0)
array array_diff_ukey ( array array1, array array2 [, array ..., callback key_compare_func] )

Compares the keys from array1 against the keys from array2 and returns the difference. This function is like array_diff() except the comparison is done on the keys instead of the values.

Unlike array_diff_key() an user supplied callback function is used for the indices comparision, not internal function.

Parameters

array1: The array to compare from
array2: An array to compare against
...: More arrays to compare against
key_compare_func: callback function to use. The callback function must return an integer less than, equal to, or greater than zero if the first argument is considered to be respectively less than, equal to, or greater than the second.

Return Values

Returns an array containing all the entries from array1 that are not present in any of the other arrays.

Examples

Example 241. array_diff_ukey() example

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<?php
function key_compare_func($key1, $key2)

{

    if ($key1 == $key2)

        return 0;

    else if ($key1 > $key2)

        return 1;

    else

        return -1;

}

$array1 = array('blue'  => 1, 'red'  => 2, 'green'  => 3, 'purple' => 4);
$array2 = array('green' => 5, 'blue' => 6, 'yellow' => 7, 'cyan'   => 8);

var_dump(array_diff_ukey($array1, $array2, 'key_compare_func'));
?>

The above example will output:

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array(2) {

  ["red"]=>

  int(2)

  ["purple"]=>

  int(4)

}

Notes

Note:

This function only checks one dimension of a n-dimensional array. Of course you can check deeper dimensions by using array_diff_ukey($array1[0], $array2[0], 'callback_func');.