(PHP 5, PHP 7, PHP 8)

array_intersect_uassocComputes the intersection of arrays with additional index check, compares indexes by a callback function


array_intersect_uassoc(array $array, array ...$arrays, callable $key_compare_func): array

array_intersect_uassoc() returns an array containing all the values of array that are present in all the arguments. Note that the keys are used in the comparison unlike in array_intersect().



Initial array for comparison of the arrays.


Arrays to compare keys against.


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.

callback(mixed $a, mixed $b): int

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.

Return Values

Returns the values of array whose values exist in all of the arguments.


Example #1 array_intersect_uassoc() example

= array("a" => "green", "b" => "brown", "c" => "blue", "red");
$array2 = array("a" => "GREEN", "B" => "brown", "yellow", "red");

print_r(array_intersect_uassoc($array1, $array2, "strcasecmp"));

The above example will output:

    [b] => brown

See Also

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