What is NSDictionary?

What is NSDictionary?

An object representing a static collection of key-value pairs, for use instead of a Dictionary constant in cases that require reference semantics.

What is difference between Dictionary and NSDictionary?

4 Answers. Dictionary is a native Swift struct. NSDictionary is a Cocoa class. They are bridged to one another (within the usual limits), as the docs explain very clearly and fully.

What is the difference between NSDictionary and NSMutableDictionary?

Main Difference is: NSMutableDictionary is derived from NSDictionary, it has all the methods of NSDictionary. NSMutableDictionary is mutable( can be modified) but NSDictionary is immutable (can not be modified).

How do you convert NSDictionary to NSMutableDictionary?

4 Answers. Use -mutableCopy . NSDictionary *d; NSMutableDictionary *m = [d mutableCopy]; Note that -mutableCopy returns id ( Any in Swift) so you will want to assign / cast to the right type.

Is NSDictionary ordered?

NSDictionary keys & values are not ordered.

How do I create an NSDictionary in Objective-C?

Objective-C Language NSDictionary

1. Create# NSDictionary *dict = [[NSDictionary alloc] initWithObjectsAndKeys:@”value1″, @”key1″, @”value2″, @”key2″, nil];
2. NSDictionary to NSArray.
3. NSDictionary to NSData.
4. NSDictionary to JSON.
5. Block Based Enumeration.
6. Fast Enumeration.

Is Swift dictionary mutable?

If you assign a created dictionary to a variable, then it is always mutable which means you can change it by adding, removing, or changing its items. But if you assign a dictionary to a constant, then that dictionary is immutable, and its size and contents cannot be changed.

What is NSMutableArray Objective C?

The NSMutableArray class declares the programmatic interface to objects that manage a modifiable array of objects. This class adds insertion and deletion operations to the basic array-handling behavior inherited from NSArray . NSMutableArray is “toll-free bridged” with its Core Foundation counterpart, CFMutableArray .

What is mutable dictionary?

Definition of mutable 1 : prone to change : inconstant mutable opinions. 2a : capable of change or of being changed mutable laws. b : capable of or liable to mutation mutable vowels a mutable gene.

Are Dictionaries mutable?

Dictionary is a built-in Python Data Structure that is mutable. It is similar in spirit to List, Set, and Tuples.

Is dict a keyword in Python?

The dict() constructor creates a dictionary in Python. Hence, the keyword argument of the form kwarg=value is passed to dict() constructor to create dictionaries. dict() doesn’t return any value (returns None ).