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NSMutableDictionary

A dynamic collection of objects associated with unique keys.

Declaration

class NSMutableDictionary

Overview

In Swift, you can use this type instead of a Dictionary variable in cases that require reference semantics.

The NSMutableDictionary class declares the programmatic interface to objects that manage mutable associations of keys and values. It adds modification operations to the basic operations it inherits from NSDictionary.

NSMutableDictionary is “toll-free bridged” with its Core Foundation counterpart, CFMutableDictionary. See Toll-Free Bridging for more information on toll-free bridging.

Setting Values Using Subscripting

In addition to the provided instance methods, such as setObject(_:forKey:), you can access NSDictionary values by their keys using subscripting.

Subclassing Notes

There should typically be little need to subclass NSMutableDictionary. If you do need to customize behavior, it is often better to consider composition rather than subclassing.

Methods to Override

In a subclass, you must override both of its primitive methods:

You must also override the primitive methods of the NSDictionary class.

Topics

Creating and Initializing a Mutable Dictionary

Adding Entries to a Mutable Dictionary

Removing Entries From a Mutable Dictionary

Initializers

Instance Methods

Subscripts

Default Implementations