14.13 Adding and Removing Dictionary Entries

Items may be added to a dictionary using the following key subscripting syntax:

dictionaryVariable[key] = value

For example, to add a new key-value pair entry to the books dictionary:

bookDict["300-898871"] = "The Overlook"

Removal of a key-value pair from a dictionary may be achieved either by assigning a nil value to the entry, or via a call to the removeValueForKey method of the dictionary instance. Both code lines below achieve the same result of removing the specified entry from the books dictionary:

bookDict["300-898871"] = nil

bookDict.removeValue(forKey: "300-898871")