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PHP array_udiff() Function

PHP Array Reference Complete PHP Array Reference

Definition and Usage

The array_udiff() function compares two or more arrays, in a user-made function, and returns an array containing the elements from the first array, if the user-made function allows it. The user-made function compares array values, and returns a numeric value, a positive number (1) if the returned array should contain this element, and 0, or a negative number (-1), if not.

Syntax

array_udiff(array1,array2,array3...,function)

Parameter Description
array1 Required. The first array is the array that the others will be compared with
array2 Required. An array to be compared with the first array
array3 Optional. An array to be compared with the first array
function Required. The name of the user-made function

Tips and Notes

Tip: You can compare the first array with one array, or as many as you like.

Note: Only the value is used in the comparison.

Example

<?php
function myfunction($v1,$v2) 
{
if ($v1===$v2)
	{
	return 0;
	}
return 1;
}
$a1=array("a"=>"Cat","b"=>"Dog","c"=>"Horse");
$a2=array(1=>"Cat",2=>"Dog",3=>"Fish");
print_r(array_udiff($a1,$a2,"myfunction"));
?>

The output of the code above will be:

Array ( [c] => Horse )

PHP Array Reference Complete PHP Array Reference

From http://www.w3schools.com (Copyright Refsnes Data)