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.
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.
How do I create an NSArray in Objective C?
Creating an Array Object The NSArray class contains a class method named arrayWithObjects that can be called upon to create a new array object and initialize it with elements. For example: NSArray *myColors; myColors = [NSArray arrayWithObjects: @”Red”, @”Green”, @”Blue”, @”Yellow”, nil];
How do I create an NSDictionary in Objective C?
Objective-C Language NSDictionary
- Create# NSDictionary *dict = [[NSDictionary alloc] initWithObjectsAndKeys:@”value1″, @”key1″, @”value2″, @”key2″, nil];
- NSDictionary to NSArray.
- NSDictionary to NSData.
- NSDictionary to JSON.
- Block Based Enumeration.
- Fast Enumeration.
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).
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.
What is the difference between dictionary 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.
Is NSDictionary thread safe?
NSMutableDictionary isn’t designed to be thread-safe data structure, and simply marking the property as atomic , doesn’t ensure that the underlying data operations are actually performed atomically (in a safe manner).
What is NSArray in IOS Swift?
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 . Because foo changes the local value of a and bar changes the reference.
What is the key difference between NSArray and NSMutableArray?
NSArray and its subclass NSMutableArray manage ordered collections of objects called arrays. NSArray creates static arrays, and NSMutableArray creates dynamic arrays. You can use arrays when you need an ordered collection of objects. NSArray is “toll-free bridged” with its Core Foundation counterpart, CFArray .
What is NSData in IOS?
A static byte buffer that bridges to Data ; use NSData when you need reference semantics or other Foundation-specific behavior. Language. SwiftObjective-C.
What is difference between dictionary and NSDictionary?
