The array_uintersect_assoc Function

The array_uintersect_assoc function returns an array containing all the elements of the first array that are present in all other arrays. Comparison of keys and values is performed using a user-defined callback function.

Syntax

phparray_uintersect_assoc(array $array1, array $array2, ..., callable $value_compare_func): array

Example

Comparing arrays with a custom function:

php<?php
  function compare($a, $b) {
    if ($a === $b) {
      return 0;
    }
    return ($a > $b) ? 1 : -1;
  }

  $array1 = ["a" => "green", "b" => "brown", "c" => "blue"];
  $array2 = ["a" => "GREEN", "B" => "brown", "c" => "blue"];
  
  print_r(array_uintersect_assoc($array1, $array2, "strcasecmp"));
?>

Code execution result:

phpArray
(
  [a] => green
  [c] => blue
)

Example

Comparison with numeric values:

php<?php
  function numCompare($a, $b) {
    return $a <=> $b;
  }

  $array1 = [10 => "apple", 20 => "banana", 30 => "cherry"];
  $array2 = [10 => 10, 20 => "banana", 40 => "cherry"];
  
  print_r(array_uintersect_assoc($array1, $array2, "numCompare"));
?>

Code execution result:

phpArray
(
  [20] => banana
)

See Also