php man page for array_udiff_assoc

ARRAY_UDIFF_ASSOC(3)							 1						      ARRAY_UDIFF_ASSOC(3)

array_udiff_assoc - Computes the difference of arrays with additional index check, compares data by a callback function

SYNOPSIS
       array array_udiff_assoc (array  $array1, array  $array2, [array	$...], callable  $value_compare_func)

DESCRIPTION
	Computes the difference of arrays with additional index check, compares data by a callback function.

       Note

	       Please  note  that  this  function only checks one dimension of a n-dimensional array. Of course you can check deeper dimensions by
	      using, for example, array_udiff_assoc($array1[0], $array2[0], "some_comparison_func");.

PARAMETERS
	      o $array1
		- The first array.

	      o $array2
		- The second array.

	      o $value_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
       array_udiff_assoc(3)  returns an array containing all the values from $array1 that are not present in any of the other arguments. Note that
       the keys are used in the comparison unlike array_diff(3) and array_udiff(3). The comparison of arrays' data is performed by using an  user-
       supplied  callback.  In this aspect the behaviour is opposite to the behaviour of array_diff_assoc(3) which uses internal function for com-
       parison.

EXAMPLES
       Example #1

	      array_udiff_assoc(3) example

	      <?php
	      class cr {
		  private $priv_member;
		  function cr($val)
		  {
		      $this->priv_member = $val;
		  }

		  static function comp_func_cr($a, $b)
		  {
		      if ($a->priv_member === $b->priv_member) return 0;
		      return ($a->priv_member > $b->priv_member)? 1:-1;
		  }
	      }

	      $a = array("0.1" => new cr(9), "0.5" => new cr(12), 0 => new cr(23), 1=> new cr(4), 2 => new cr(-15),);
	      $b = array("0.2" => new cr(9), "0.5" => new cr(22), 0 => new cr(3), 1=> new cr(4), 2 => new cr(-15),);

	      $result = array_udiff_assoc($a, $b, array("cr", "comp_func_cr"));
	      print_r($result);
	      ?>

	      The above example will output:

	      Array
	      (
		  [0.1] => cr Object
		      (
			  [priv_member:private] => 9
		      )

		  [0.5] => cr Object
		      (
			  [priv_member:private] => 12
		      )

		  [0] => cr Object
		      (
			  [priv_member:private] => 23
		      )
	      )

	In our example above you see the "1" => new cr(4) pair is present in both arrays and thus it is not in the output from the function.

SEE ALSO
       array_diff(3),  array_diff_assoc(3),  array_diff_uassoc(3),   array_udiff(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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