What is a NSDictionary object?

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.

What is NSCopying in Swift?

NSCopying can be used in Swift as a generic way to create copies of classes (reference types), and as a bonus, making a Swift type inherit from NSCopying will also allow it to make use of the copy property accessor in Objective-C bridges.

Is NSDictionary mutable?

NSDictionary is mutable, So if you want to make any modifications to that you need to convert it as NSMutableDictionary and make changes.

What is @nscopying?

A protocol that objects adopt to provide functional copies of themselves.

Are Dicts mutable Python?

A dictionary is an unordered and mutable Python container that stores mappings of unique keys to values. Dictionaries are written with curly brackets ({}), including key-value pairs separated by commas (,).

Is UIKit thread-safe?

Start From Why UIKit is not Thread-Safe As we can see, most of the components in UIKit is described as nonatomic `, this means there are not thread safe. And it is unrealistic to design all the properties as thread-safe in UIKit because it is such a huge framework.

Is NSSet thread-safe?

The documentation on NSSet objectEnumeration says: When this method is used with mutable subclasses of NSSet, your code shouldn’t modify the set during enumeration. If you intend to modify the set, use the allObjects method to create a “snapshot” of the set’s members.

How is the copy method defined in NSCopying?

NSCopying declares one method, copy(with:), but copying is commonly invoked with the convenience method copy(). The copy() method is defined for all objects inheriting from NSObject and simply invokes copy(with:) with the default zone. Your options for implementing this protocol are as follows:

Which is an example of an NSDictionary class?

The NSDictionary class declares the programmatic interface to objects that manage immutable associations of keys and values. For example, an interactive form could be represented as a dictionary, with the field names as keys, corresponding to user-entered values.

Where are NSNumber and NSString stored in NSDictionary?

In NSDictionary, Entries are stored in the form of buy propecia online key value pairs. A Dictionary can hold NSNumber, NSString, NSArray, ..etc and their mutable objects. Below is the simple Dictionary in JSON format.

How to create a dictionary using NSMutableDictionary?

NSMutableDictionary is mutable ( can be modified) but NSDictionary is immutable (can not be modified). To create a dictionary you can use static methods, or initialization methods. + (instancetype)dictionaryWithObject: (id)object forKey: (id )key;