在php中，如何根据特定的（在本例中为最后一个）路径片段对路径数组进行排序？

Question

I have an array like so:

[0] => /home/user/public_html/things/1 - First thing/
[1] => /home/user/public_html/things/3 - Third thing/
[2] => /home/user/public_html/things/2 - Second thing/

What's the straightforward way to sort this array so the 'things' go 1, 2, 3?

I've used natsort() on just the last path-fragment but it's not proving straightforward to use... I chopped the rest of the path off, sorted, then put it back on but that's ugly and it can change in the mean time so I'm hoping for a better way than that.

Any and all suggestions would be greatly appreciated, I'm sure there's several ways to approach this :)

Answer 1

Taking your question as it stands (sort an array of paths based on a specific path-fragment), I thought of a function that would allow you to specify the fragment you want the paths to be sorted on.

As the paths in the example only differ in their last part, the above is not very interesting when applied on that example. So I will use a slightly different list:

$paths = [
    '/home/user/public_html/things/sub/1',
    '/home/user/public_html/things/3',
    '/home/admin/public_html/things/2'
];

function build_sorter($part) {
    return function ($a, $b) use ($part) {
        return strnatcmp(
            implode("/", array_slice(explode("/", $a), $part)),
            implode("/", array_slice(explode("/", $b), $part))
        );
    };
}

// sort by second part in paths:
usort($paths, build_sorter(2));
print_r ($paths);

The output generated has put the "admin" folder first:

   Array (
     [0] => /home/admin/public_html/things/2
     [1] => /home/user/public_html/things/3
     [2] => /home/user/public_html/things/sub/1
   ) 

Sorting by the last part would go like this:

usort($paths, build_sorter(-1));
print_r ($paths);

Output:

   Array (
     [0] => /home/user/public_html/things/sub/1
     [1] => /home/admin/public_html/things/2
     [2] => /home/user/public_html/things/3
   ) 

So the argument you pass to builder_sort is the offset (positive from left, negative from right) of the part of the paths you want to base your sort on.