What is a protocol ObjC?
What is a protocol ObjC?
Objective-C allows you to define protocols, which declare the methods expected to be used for a particular situation. Protocols are implemented in the classes conforming to the protocol. We have a delegate object that holds the reference of the calling object that implements the protocol.
What is Category protocol?
Protocol categories contain methods that are automatically applied to any class that declares itself to conform to PROTOCOL.” There is an accompanying macro you also have to use in your implementation file.
What is the difference between category VS extension?
Category and extension both are basically made to handle large code base, but category is a way to extend class API in multiple source files while extension is a way to add required methods outside the main interface file.
What is the use of category in Objective-C?
Categories provide the ability to add functionality to an object without subclassing or changing the actual object. A handy tool, they are often used to add methods to existing classes, such as NSString or your own custom objects.
What is difference between protocol and delegate?
We can say Protocol as a set of rules. That rules can be optional or required like we have to use in protocol. Delegates is a message passing technique in objective C and swift. An object has to take care of that message.
What is ID type in Objective-C?
“id” is a data type of object identifiers in Objective-C, which can be use for an object of any type no matter what class does it have. “id” is the final supertype of all objects. Although being a pointer type, it’s a pointer that’s treated by the Objective C compiler in a very special way.
What is the difference between category and extension in Objective-C?
Categories are an Objective-C language feature that let you add new methods to an existing class, much like C# extensions. Objective-C’s extensions are a special case of categories that let you define methods that must be declared in the main implementation block.
What is category in Swift?
(Unlike Objective-C categories, Swift extensions do not have names.) Uses: Categories are a way to modularize a class by spreading its implementation over many files. Extensions provide similar functionality. One of the most common uses of categories is to add methods to built-in data types like NSString or NSArray .
What are swift categories?
Categories are a way to modularize a class by spreading its implementation over many files. Extensions provide similar functionality. One of the most common uses of categories is to add methods to built-in data types like NSString or NSArray .
What can be achieved with category and extension?
A category allows you to add methods to an existing class—even to one for which you do not have the source. Categories are a powerful feature that allows you to extend the functionality of existing classes without subclassing.
What is the difference between delegate and datasource?
A data source is like a delegate except that, instead of being delegated control of the user interface, it is delegated control of data. A data source is an outlet held by NSView and UIView objects such as table views and outline views that require a source from which to populate their rows of visible data.
What is the use of objc in it?
It also provides a number of utility functions and types that make it easier to integrate Python and Objective-C code. The module objc defines a number of functions whose names start with an underscore. Those functions are private and should not be used, they can be removed from release without warning.
What is object Objective C protocol?
Objective-C Protocols. Objective-C allows you to define protocols, which declare the methods expected to be used for a particular situation. Protocols are implemented in the classes conforming to the protocol.
What is objectobjective-C (OOC)?
Objective-C allows you to define protocols, which declare the methods expected to be used for a particular situation. Protocols are implemented in the classes conforming to the protocol.
How do you declare a category in Objective-C?
The syntax to declare a category uses the @interface keyword, just like a standard Objective-C class description, but does not indicate any inheritance from a subclass. Instead, it specifies the name of the category in parentheses, like this −
