[SOLVED] Move some items to the end of the array if they fulfill a specific condition

Move some items to the end of the array if they fulfill a specific condition

I have an array of paths that I would like to sort ...

Array
(
    /something/foo1
    /something/special/foo2
    /something/foo3
    /something/special/foo4
    /something/foo5
    /something/special/foo6
)

... so that all paths that contain /special/ end up at the end of the array like this:

Array
(
    /something/foo1
    /something/foo3
    /something/foo5
    /something/special/foo2
    /something/special/foo4
    /something/special/foo6
)

The original sort order of paths must remain the same (so 1,2,3,4,5,6 => 1,3,5,2,4,6). Is there an elegant way to do this? Can this be implemented by using the usort function?

Solution

you can use unset and append [], like so

$x = array(1,2,3);
$x[] = $x[1];
unset($x[1]);
print_r($x);

Array
(
    [0] => 1
    [2] => 3
    [3] => 2
)

You can thus loop over the array, test each element, and flip to the end the ones that contain the pattern.

$len = count($a);
for ($i=0; $i<$len; $i++) {
    if (...) {
        $a[] = $a[i];
        unset($a[i]);
    }
}

Edit: php's arrays are lists, hashes and arrays simultaneously. It is possible to move an element to the end while retaining its index! For example

$a = array(1,2,3);

$t = $a[1];
unset($a[1]);
$a[1] = $t;

print_r($a);
Array
(
    [0] => 1
    [2] => 3
    [1] => 2
)