Arrays

An array is an ordered collection of elements of the same type, and they are used for pretty much anything that requires storing things in a certain order, such as the contents of lists in apps. It works like similar types in other languages.

Working with Arrays

Here are some of the most common operations on arrays:

• Create an array:

  let a = [0,1,2,3,4] // array literal

• Join two arrays:

  var b = a + [5,6]

• Repeat a value:

  let c = Array(repeating: 4.1, count: 3)

• Create an array from any sequence (a String is a Sequence of Character):

  var d = Array("The ☀ and 🌙 ")

• Add values to the end of an array:

  b.append(10) // append one element

• Append an entire array:

  b += a
  b.append(contentsOf: a) // append a sequence

• Get the length of an array:

  b.count

• Iterate over all elements:

  for nr in b {
           // do something with 'nr'
         }

Here are their abilities, represented by some of the protocols they conform to:

• BidirectionalCollection can go backwards from any index (except...