array_uintersect

(PHP 5, PHP 7)

array_uintersect — Computes the intersection of arrays, compares data by a callback function

Description

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

Computes the intersection of arrays, compares data by a callback function.

Parameters

array1: The first array.
array2: The second array.
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

Returns an array containing all the values of array1 that are present in all the arguments.

Examples

Example #1 array_uintersect() example


<?php
$array1 = array("a" => "green", "b" => "brown", "c" => "blue", "red");
$array2 = array("a" => "GREEN", "B" => "brown", "yellow", "red");

print_r(array_uintersect($array1, $array2, "strcasecmp"));
?>

The above example will output:

Array
(
    [a] => green
    [b] => brown
    [0] => red
)

User Contributed Notes

Nate at RuggFamily dot com

9 years ago


I want to stress that in the user function, you do need to return either a 1 or a -1 properly; you cannot simply return 0 if the results are equal and 1 if they are not.  

The following code is incorrect:

<?php
function myfunction($v1,$v2) 
{
if ($v1===$v2)
    {
    return 0;
    }
return 1;
}

$a1=array(1, 2, 4);
$a2=array(1, 3, 4);
print_r(array_uintersect($a1,$a2,"myfunction"));
?>

This code is correct:

<?php
function myfunction($v1,$v2) 
{
if ($v1===$v2)
    {
    return 0;
    }
if ($v1 > $v2) return 1;
return -1;
}
$a1=array(1, 2, 4);
$a2=array(1, 3, 4);
print_r(array_uintersect($a1,$a2,"myfunction"));
?>