(PHP 5 >= 5.1.0, PHP 7, PHP 8)
array_intersect_ukey — Computes the intersection of arrays using a callback function on the keys for comparison
array_intersect_ukey() returns an array
containing all the values of array
which have matching keys that are present in all the arguments.
arrayInitial array for comparison of the arrays.
arraysArrays to compare keys against.
key_compare_funcThe 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.
Returning non-integer values from the comparison
function, such as float, will result in an internal cast to
int of the callback's return value. So values such as
0.99 and 0.1 will both be cast to an
integer value of 0, which will compare such values as equal.
Returns the values of array whose keys exist
in all the arguments.
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 array.