What is a NSDictionary?

What is a NSDictionary?

NSDictionary is a Cocoa class. They are bridged to one another (within the usual limits), as the docs explain very clearly and fully. It’s exactly parallel to Array and NSArray. Follow this answer to receive notifications.

What is a NSDictionary object?

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

Is NSDictionary thread safe?

In general, the collection classes (for example, NSMutableArray , NSMutableDictionary ) are not thread-safe when mutations are concerned. That is, if one or more threads are changing the same array, problems can occur.

What is NSMutableArray Objective-C?

NSArray is Objective-C’s general-purpose array type. It represents an ordered collection of objects. NSArray is immutable, so we cannot dynamically add or remove items.

What is NSMutableArray in Swift?

Overview. 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 .

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 .

How do I check if Nsdictionary is empty in Objective C?

if (myDict. count) NSLog(@”Dictionary is not empty”); else NSLog(@”Dictionary is empty”); Every number that is 0 equals to @NO . Every number that is not 0 equals to @YES .

Is Dictionary thread safe Swift?

Dictionaries in Swift are not thread safe , they lead to wierd crashes which are very hard to debug. This class solves this problem by using a dictionary whose accesses are made thread safe by using a concurrent queue with a barrier.