PHP Manual: Computes the intersection of arrays using a callback function on the keys for comparison

Description

array array_intersect_ukey ( array $array1 , array $array2 [, array $... ], callable $key_compare_func )

array_intersect_ukey returns an array containing all the values of array1 which have matching keys that are present in all the arguments.

Parameters

array1: Initial array for comparison of the arrays.
array2: First array to compare keys against.
...: Variable list of array arguments to compare keys against.
key_compare_func: The comparison 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. Note that before PHP 7.0.0 this integer had to be in the range from -2147483648 to 2147483647.

int callback ( mixed $a, mixed $b )

Return Values

Returns the values of array1 whose keys exist in all the arguments.

Examples

Example #1 array_intersect_ukey example


<?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_intersect_ukey($array1, $array2, 'key_compare_func'));
?>

The above example will output:

array(2) {
  ["blue"]=>
  int(1)
  ["green"]=>
  int(3)
}

In our example you see that only the keys 'blue' and 'green' are present in both arrays and thus returned. Also notice that the values for the keys 'blue' and 'green' differ between the two arrays. A match still occurs because only the keys are checked. The values returned are those of array1.

array_intersect_ukey

Description

Parameters

Return Values

Examples

See Also