What is Swift NSArray?

What is Swift NSArray?

NSArray is an immutable Objective C class, therefore it is a reference type in Swift and it is bridged to Array . NSMutableArray is the mutable subclass of NSArray .

What is NSSet in Swift?

NSSet is “toll-free bridged” with its Core Foundation counterpart, CFSetRef . See Toll-Free Bridging for more information on toll-free bridging. In Swift, use this class instead of a Set constant in cases where you require reference semantics.

What’s a difference between NSArray and NSSet?

The main difference is that NSArray is for an ordered collection and NSSet is for an unordered collection. There are several articles out there that talk about the difference in speed between the two, like this one. If you’re iterating through an unordered collection, NSSet is great.

Why set is faster than array?

Testing whether an object is contained in a set is faster than testing for membership of an array. As it is a static collection type it will not be possible to add or remove objects after initialization. This might be an important reason to go for an Array instead.

What is a CFString?

CFString is an opaque type that defines the characteristics and behavior of CFString objects. Values of type CFStringRef may refer to immutable or mutable strings, as CFMutableString objects respond to all functions intended for immutable CFString objects.

Is AnyObject a protocol?

AnyObject is a protocol to which all classes implicitly conform. In fact, the standard library contains a type alias AnyClass representing AnyObject. Type . You can use AnyObject if you need the flexibility of an untyped object.

What can AnyObject represent?

instance of any class type
AnyObject is a protocol that can represent an instance of any class type. It also has a more general counterpart, Any , which can represent any type at all (including structs and enums).

Is Nsmutablearray ordered?

The answer is yes, the order of the elements of an array will be maintained – because an array is an ordered collection of items, just like a string is an ordered sequence of characters…