The array_uintersect Function

The array_uintersect function computes the intersection of arrays using a callback function for value comparison. It returns an array containing all the values from the first array that are present in all the other arrays. Value comparison is done through a user-defined callback function.

Syntax

phparray_uintersect(array $array1, array $array2, ..., callable $value_compare_func): array;

Example

Find the intersection of two arrays by comparing their values using a callback function:

php<?php
  $array1 = [1, 2, 3, 4, 5];
  $array2 = [2, 4, 6, 8, 10];
  
  $res = array_uintersect($array1, $array2, function($a, $b) {
    if ($a === $b) {
      return 0;
    }
    return ($a > $b) ? 1 : -1;
  });
  
  print_r($res);
?>

Code execution result:

php[2, 4]

Example

Comparing string arrays using a custom function:

php<?php
  $array1 = ['a', 'b', 'c', 'd', 'e'];
  $array2 = ['b', 'd', 'f', 'h', 'j'];
  
  $res = array_uintersect($array1, $array2, function($a, $b) {
    return strcmp($a, $b);
  });
  
  print_r($res);
?>

Code execution result:

php['b', 'd']

See Also