How to sort this multidimensional array by one of its key's?

[the5thace]

I'm looking to sort this multidimensional array according to its integer value under the key name 'rank'.

 

In other words $r_set contains the combined results of a number of search engines and each result is assigned a 'rank' according to which I want the array to be sorted.

 

$r_set contents look like this ->

$google[$google_count] = array 
('url'=>$item->link, 
 'url_title'=>$item->title,    
 'snippet' =>$item->htmlSnippet,
 'rank' => 100-$google_count,
 'engine' => 'Google'); 
 $google_count++;

I load a number of these kinds of results(.ie $google[google_count] and others like it) in to $r_set when they have the same structure. 

 

I want $r_set to be sorted by its 'rank' key starting highest to lowest. 

 

 

 

 

 

[requinix]

Either usort and you write a function that can compare two of those arrays to determine which comes first,

function goggles($a, $b) {
    if ($a["rank"] != $b["rank"]) {
        return $a["rank"] - $b["rank"];
    } else {
        // same rank so use something else to break the tie
    }
}
usort($google, "goggles");

or array_multisort and you create a separate 1D array containing just the values you want to sort by.

// as if $goggles = array($google[0]["rank"], $google[1]["rank"], $google[2]["rank"], ...)
array_multisort($google, $goggles);

[Barand]

For a descending sort you need to return

 

$b['rank'] - $a['rank']