Reverse sort an array of arrays

[kreut]

Hello!

 

Is it possible to reverse sort an array by looking at specific values if the array is multi-dimensional?

 

Array ( 
[0] => Array ( [question_id] => 34 [ratio] => .2 )
[1] => Array ( [question_id] => 45 [ratio] => .7 )
[2] => Array ( [question_id] => 51 [ratio] => 1 )
[3] => Array ( [question_id] => 55 [ratio] => 0.5 )
[4] => Array ( [question_id] => 57 [ratio] => 0 ) )

 

For example, if I wanted to reverse sort by ratio, the new array of arrays should be:

 

Array ( 
[0] => Array ( [question_id] => 51 [ratio] => 1 )
[1] => Array ( [question_id] => 45 [ratio] => .7 )
[2] => Array ( [question_id] => 55 [ratio] => 0.5 )
[3] => Array ( [question_id] => 34 [ratio] => .2 )
[4] => Array ( [question_id] => 57 [ratio] => 0 ) )

 

 

 

Thanks!

 

-Eric

[AbraCadaver]

I was just going to post a link to array_multisort(), but (not tested, you get the idea):

 

foreach($array as $key => $val) {
    $ratio[$key] = $val['ratio'];
}
array_multisort($ratio, SORT_DESC, $array);

print_r($array);

[AyKay47]

I know this isn't what you asked, but if you wanted to sort each array separately you can write it like this

 

$array = Array ( 
[0] => Array ( [question_id] => 51 [ratio] => 1 )
[1] => Array ( [question_id] => 45 [ratio] => .7 )
[2] => Array ( [question_id] => 55 [ratio] => 0.5 )
[3] => Array ( [question_id] => 34 [ratio] => .2 )
[4] => Array ( [question_id] => 57 [ratio] => 0 ) )

array_multisort($array[0],SORT_DESC);
array_multisort($array[1],SORT_DESC,SORT_NUMERIC); //etc.....

[kreut]

Thanks so much to both of you!

 

-Eric