Question

I got a 2d-array containing a “column” on which this whole array is to be sorted. As I learned here, it is quite straightforward using array_multisort. My problem is, that this to be sorted over column contains values that needs to be compared in an unusual way. So I thought of something like this:

function main(){
    $toBeSorted = array(array(...), ..., array(...));
    $sortColumnIndex = n;
    $sort_column = array();

    //Code copied from provided link
    foreach ($toBeSorted as $row)
        $sort_column []= $row[$sortColumnIndex];

    array_multisort($this->comparator(),$sort_column, $toBeSorted);
}

function comparator(a,b){
    return 1;
}

As you can see, I want to pass my comparator to that sort-function. I probably think to much in a non-php way.

Answer 1

I solved it by transforming my sorting space in one, that array_multisort can handle:

...

$sortColumn = array();
foreach($toBeSorted as $value){
     $sortColumn[] = $this->transform($value);
}
array_multisort($sortColumn, $toBeSorted);

...

my transformation function simply does everything I imagined the callback would do.

function transform($value){
    //i.e. return real part of complex number
    //or parse strings or any kind of strange datatypes
}