如何排序多维数组的第二个索引？

Question

Not sure if titled the question correctly but first of all

What kind of array is this? Second how do I sort the second index by ASC or DESC

For example where it says float(.... How do I sort that?

Been trying to use rsort and arsort but just not getting the results I need.

If I have code like this

array(24) { 
           [0]=> array(2) 
           { [0]=> string(4) "AAPL" [1]=> float(64.756994020789) }

           [1]=> array(2) 
           { [0]=> string(3) "AMD" [1]=> float(57.268267955388) }

           [2]=> array(2) 
           { [0]=> string(4) "BABA" [1]=> float(57.24625652504) } 

           [3]=> array(2) 
           { [0]=> string(4) "BIDU" [1]=> float(65.24289909913) }

           [4]=> array(2) 
           { [0]=> string(5) "BRK.B" [1]=> float(52.178207183616) }

           [5]=> array(2) 
           { [0]=> string(3) "CAT" [1]=> float(50.412401981782) }

           [6]=> array(2) 
           { [0]=> string(3) "DIA" [1]=> float(55.683323570131) }

           [7]=> array(2) 
           { [0]=> string(3) "DIS" [1]=> float(47.435360931467) }

           } 

           rsort($array);
           var_dump($array);

Answer 1

Use usort with your custom sorting function:

usort($array, function($a, $b) { return $a[1] - $b[1]; });
// as of php7
usort($array, function($a, $b) { return $a[1] <=> $b[1]; });