PHP array_udiff() Function

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# PHP array_udiff() Function

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 )

Complete PHP Array Reference

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