php usort on different values

Question

I am using this usort function to sort the array by value:

    function cmp($a, $b)
    {
        if ($a["value"] == $b["value"])
        { return 0; }
        return ($a["value"] < $b["value"]) ? -1 : 1;
    }

Now, each object also has an "active" field as well, that is: $a["active"]. I would like to have the sorted array to have first the active ones (1) ordered by value, then, when all of them are sorted, the inactive (0) ones. I tried using another usort after this but it doesn't work nicely, it somewhat scrambles them.

Thanks in advance.

Answer 1

function cmp($a,$b){
    if ($a["active"]==$b["active"]){
        if($a["value"]==$b["value"])
            return 0;
        return $a["value"]>$b["value"])?1:-1;
    }
    return $a["active"]>$b["active"]?1:-1;
}

Untested - but I think it'll work. A good resource for this sort of stuff (but not this particular example, unfortunately for you): http://www.the-art-of-web.com/php/sortarray/

Answer 2

Simply add the active stuff as another comparison in your function:

if ($a['active'] > $b['active'])
   return 1;
} else if ($a['value'] == $b['value']) {
   return 0;
} else {
   return ($a['value'] < $b['value']) ? -1 : 1;
}