Arrays are one of our favorite parts of PHP because the syntax is smart and easy to read and yet manages to be as powerful as you could want. You need to know four pieces of jargon to understand arrays:
An array is made up of many elements.
Each element has a key that defines its place in the array. An array can have only one element with a given key.
Each element also has a value, which is the data associated with the key.
Each array has ...