Learning PHP 7

Arrays

If you have some experience with other programming languages or data structures in general, you might be aware of two data structures that are very common and useful: lists and maps. A list is an ordered set of elements, whereas a map is a set of elements identified by keys. Let's see an example:

List: ["Harry", "Ron", "Hermione"]

Map: {
  "name": "James Potter",
  "status": "dead"
}

The first element is a list of names that contains three values: Harry, Ron, and Hermione. The second one is a map, and it defines two values: James Potter and dead. Each of these two values is identified with a key: name and status respectively.

In PHP, we do not have lists and maps; we have arrays. An array is a data structure that implements both, a list and a ...