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.
An array can be created by the
array() language construct. It takes as parameters any number of comma-separated key => value pairs.
A key may be either an integer or a string. If a key is the standard representation of an integer, it will be interpreted as such (i.e. "8" will be interpreted as 8, while "08" will be interpreted as "08"). Floats in key are truncated to integer. The indexed and associative array types are the same type in PHP, which can both contain integer and string indices.
<?php $arr = array( 'foo' => 'bar', 42 => true ); echo $arr['foo']; // bar echo $arr; // 1 ?>