2006/12/25, Leo Liu <kkl_sg@xxxxxxxxx>:
Hi,
I try to intersect associative array and it seems to fail to do so. Can
anyone show me a walk around?
For example I have
array1
Array
(
[0] => Array
(
[imageID] => 1
)
[1] => Array
(
[imageID] => 2
)
[2] => Array
(
[imageID] => 3
)
[3] => Array
(
[imageID] => 4
)
)
And array 2
Array
(
[0] => Array
(
[imageID] => 6
)
[1] => Array
(
[imageID] => 3
)
)
After intersection instead of me getting 3 as a result, I got the array
1 unchanged. Seems like intersection doesn't take place at all. Anyway to
solve this problem?
Regards,
Leo
Reality starts with Dream
Quote from php manual, in the reference for the array_intersect function:
*Note: * Two elements are considered equal if and only if (string) $elem1
=== (string) $elem2. In words: when the string representation is the same.
That's why array_intersect isn't working with your arrays.
If you're using PHP5 you could use array_uintersect, and compare the items
by the imageID:
function compareByImageID($elem1, $elem2) {
return $elem1['imageID'] - $elem2['imageID'];
}
$intersection = array_uinsersect($array1, $array2, 'compareByImageID');
Or you can do the following, which works in PHP4, but is not as versatile as
array_uintersect:
class InArrayFilter {
var $arr;
function InArrayFilter($arr) {
$this->arr = $arr;
}
function filterFunction($elem) {
return in_array($elem, $this->arr);
}
}
$filter = new InArrayFilter($array2);
$intersection = array_filter($array1, array($filter, 'filterFunction'));
