PHP associative arrays (as well as numeric arrays) are ordered, and PHP supplies various functions to deal with the array key ordering like ksort()
, uksort()
, and krsort()
Further, PHP allows you to declare arrays with numeric keys out of order:
$a = array(3 => 'three', 1 => 'one', 2 => 'two');
print_r($a);
Array
(
[3] => three
[1] => one
[2] => two
)
// Sort into numeric order
ksort($a);
print_r($a);
Array
(
[1] => one
[2] => two
[3] => three
)
An array in PHP is actually an ordered map. A map is a type that associates values to keys. This type is optimized for several different uses; it can be treated as an array, list (vector), hash table (an implementation of a map), dictionary, collection, stack, queue, and probably more. As array values can be other arrays, trees and multidimensional arrays are also possible.