Collection types

Although we don't have space here to discuss all the methods that are made available by Array and Dictionary types, we should cover, albeit briefly, the most common operations on those objects.

Note

This section provides examples of these most common operations, and it is assumed that they are mostly self-explanatory; elaborations are added where that is possibly not the case.

Arrays

We'll start, as one usually does, with arrays.

Comparing arrays

Arrays, being value types, are compared according to their contents:

let arrA = [1, 2, 3] 
let arrB = [1, 2, 3] 
let arrC = [3, 4, 5] 

arrA == arrB 
arrA != arrC 

Both these comparisons return true, as one would expect.

Mutating an array

Adding and inserting individual elements or several elements is performed as follows:

var arr = [2, 3, 5, 7] 
arr.append(11) 

let tens = [10, 20, 30] 
arr.append(contentsOf: tens) 

arr.insert(13, at: 5) 
arr.insert(40, at: arr.endIndex) 
arr[6...8] = [17, 19, 23] 

Using arrays to create new arrays

These methods...