How do you find the value of NSDictionary?

NSMutableArray *getdata=[[NSMutableArray alloc]init]; getcat=[results objectForKey:@”data”];

What is NSDictionary in Swift?

The NSDictionary class declares the programmatic interface to objects that manage immutable associations of keys and values. (For convenience, the term dictionary refers to any instance of one of these classes without specifying its exact class membership.) A key-value pair within a dictionary is called an entry.

How do I parse a dictionary in swift 5?

“Data to dictionary swift 5” Code Answer

1. let dic = [“2”: “B”, “1”: “A”, “3”: “C”]
2. let encoder = JSONEncoder()
3. if let jsonData = try? encoder. encode(dic) {
4. if let jsonString = String(data: jsonData, encoding: . utf8) {
5. print(jsonString)
6. }
7. }

What is the difference between NSDictionary and NSMutableDictionary?

Dictionary contains an array,and that array contains dictionary. 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.

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 .

Is NSMutableDictionary 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. You must lock around spots where reads and writes occur to assure thread safety.

What is mutable dictionary?

adjective. liable or subject to change or alteration. given to changing; constantly changing; fickle or inconstant: the mutable ways of fortune. Computers. (in object-oriented programming) of or noting an object having properties whose values can change while the object itself maintains a unique identity.

What is difference between array and NSArray in Swift?

Array is a struct, therefore it is a value type in 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.

How to get a value from a dictionary in Swift?

To get the value using a key from a Swift Dictionary, use the following syntax. var value = myDictionary[key] The syntax is similar to accessing a value from an array using the index. Here, in case of the dictionary, key is playing the role of an index,

How to get a value from a key in Swift?

To get the value using a key from a Swift Dictionary, use the following syntax. The syntax is similar to accessing a value from an array using the index. Here, in case of the dictionary, key is playing the role of an index, In this example, we shall create a dictionary with initial values, and access the values from this dictionary using keys.

How does the NSDictionary class work in Swift?

In Swift, the NSDictionary class conforms to the DictionaryLiteralConvertible protocol, which allows it to be initialized with dictionary literals. For more information about object literals in Swift, see Literal Expression in The Swift Programming Language (Swift 4.1).

How do you get a value from a dictionary?

The most common way to access values in a dictionary is to use a key as a subscript. Subscripting with a key takes the following form: Subscripting a dictionary with a key returns an optional value, because a dictionary might not hold a value for the key that you use in the subscript.