Sort an array of software versions in descending order

Question

How can I sort this array of version values?

$available_databases = array(
    "4.0.1",
    "trunk",
    "branch",
    "4.1.0",
    "4.0.3"
);

so that the result is

4.1.0
4.0.3
4.0.1
branch
trunk

Answer 1

You could use PHP's built-in array operations and such to do a lot of the heavy lifting for you, thus cutting out a lot of the apparent complexity:

$names = preg_grep('/^\D/', $arr);
$versions = preg_grep('/^\d/', $arr);

usort($versions, 'version_compare');
usort($names, 'strcasecmp');

$sorted = array_merge(array_reverse($versions), $names);