Swift: Developing iOS Applications

Read-only custom subscripts

We can also make the subscript read-only by either not declaring a setter method within the subscript or by not implicitly declaring a getter or setter method. The following code shows how to declare a read-only property by not declaring a setter method:

//No getter/setters implicitly declared
subscript(index: Int) ->String {
  return names[index]
}

The following example shows how to declare a read-only property by only declaring a getter method:

//Declaring only a getter
subscript(index: Int) ->String {
  get {
    return names[index]
  }
}

In the first example, we do not define either a getter or setter method. So, Swift sets the subscript as read-only and the code acts as if it was in a getter definition. In the second example, ...