array_uintersect

(PHP 5, PHP 7)

array_uintersectComputes 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. Note that before PHP 7.0.0 this integer had to be in the range from -2147483648 to 2147483647.

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
)

See Also

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User Contributed Notes 2 notes

up
11
Nate at RuggFamily dot com
11 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"));
?>
up
0
Hayley Watson
4 months ago
As for the other "compare function" callbacks, the return value from the callback function doesn't need to be -1, 0, or 1.

cmp($a,$b) just needs to be <0, =0, or >0 depending on whether $a<$b, $a=$b, or $a>$b.
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