使用分组按两个字段值对数组进行排序

Question

UPDATE: I get array order by ID, and with groups together, as you can see, every calss come together. I want to sort it first by ID, from biggest to smallest (to reverse to array), and then in every Class to sort by the Name I will show example to make it clear.

I have this array:

Array 
(
[0] => Array
    (
        [0] => 1 //ID
        [1] => 88 //Class
        [2] => 'a' //Name
    )
[1] => Array
    (
        [0] => 2 //ID
        [1] => 88 //Class
        [2] => 'b' //Name
    )
[2] => Array
    (
        [0] => 3 //ID
        [1] => 7 //Class
        [2] => 'v' //Name
    )
[3] => Array
    (
        [0] => 4 //ID
        [1] => 332 //Class
        [2] => 'd' //Name
    )
[4] => Array
    (
        [0] => 5 //ID
        [1] => 332 //Class
        [2] => 'z' //Name
    )
)

after the process I want to get:

Array 
(
[0] => Array
    (
        [0] => 4 //ID
        [1] => 332 //Class
        [2] => 'd' //Name
    )
[1] => Array
    (
        [0] => 5 //ID
        [1] => 332 //Class
        [2] => 'z' //Name
    )
[2] => Array
    (
        [0] => 3 //ID
        [1] => 7 //Class
        [2] => 'v' //Name
    )
[3] => Array
    (
        [0] => 1 //ID
        [1] => 88 //Class
        [2] => 'a' //Name
    )
[4] => Array
    (
        [0] => 2 //ID
        [1] => 88 //Class
        [2] => 'b' //Name
    )
)

I tried to use array_multisort with 2 fields, but it's not work. anyone have ideas?

Thank

Answer 1

This isn't really what I would refer to as grouping, although I can see why you would think of it that way. Really this is just a sort with a hierarchical set of criteria rather than just a single criterion. You sort by Parent ID, then use ID to break ties. It can be done with usort .

usort($data, function($a, $b) {
    //    compare group ID
    return ($a[2] - $b[2]) ?: ($a[0] - $b[0]);
    //                        compare ID if group ID is equal
});