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.
1. Creating Arrays
An array can be created using the array() language construct. It takes any number of comma-separated key => value pairs as arguments.
array(key => value,key2 => value2,key3 => value3,...