php man page for array_diff_uassoc

ARRAY_DIFF_UASSOC(3)							 1						      ARRAY_DIFF_UASSOC(3)

array_diff_uassoc - Computes the difference of arrays with additional index check which is performed by a user supplied callback function

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

DESCRIPTION
	Compares $array1 against $array2 and returns the difference. Unlike array_diff(3) the array keys are used in the comparison.

	Unlike array_diff_assoc(3) an user supplied callback function is used for the indices comparison, not internal function.

PARAMETERS
	      o $array1
		- The array to compare from

	      o $array2
		- An array to compare against

	      o $...
		- More arrays to compare against

	      o $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.
		int callback (mixed  $a, mixed	$b)

RETURN VALUES
	Returns an array containing all the entries from $array1 that are not present in any of the other arrays.

EXAMPLES
       Example #1

	      array_diff_uassoc(3) example

	       The "a" => "green" pair is present in both arrays and thus it is not in the output from the function. Unlike this, the  pair  0	=>
	      "red" is in the output because in the second argument "red" has key which is 1.

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

	      $array1 = array("a" => "green", "b" => "brown", "c" => "blue", "red");
	      $array2 = array("a" => "green", "yellow", "red");
	      $result = array_diff_uassoc($array1, $array2, "key_compare_func");
	      print_r($result);
	      ?>

	      The above example will output:

	      Array
	      (
		  [b] => brown
		  [c] => blue
		  [0] => red
	      )

	       The equality of 2 indices is checked by the user supplied callback function.

NOTES
       Note

	       This  function only checks one dimension of a n-dimensional array. Of course you can check deeper dimensions by using, for example,
	      array_diff_uassoc($array1[0], $array2[0], "key_compare_func");.

SEE ALSO
       array_diff(3),  array_diff_assoc(3),  array_udiff(3),   array_udiff_assoc(3),   array_udiff_uassoc(3),	array_intersect(3),   array_inter-
       sect_assoc(3), array_uintersect(3), array_uintersect_assoc(3), array_uintersect_uassoc(3).

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