What is the category in Objective-C?
A category allows you to add methods to an existing class—even to one for which you do not have the source.
What is a category in Objective-C and when is it used?
You use categories to define additional methods of an existing class—even one whose source code is unavailable to you—without subclassing. You typically use a category to add methods to an existing class, such as one defined in the Cocoa frameworks.
How do you add a category in Objective-C?
Objective-C Language Categories Create a Category on XCode Open your XCode project, click on File -> New -> File and choose Objective-C file , click Next enter your category name say “CustomFont” choose file type as Category and Class as UIFont then Click “Next” followed by “Create.”
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?
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 is the difference between Category & 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 a category extension when is it used?
A brand extension (some times called a category extension) is when a brand is known for one type of product starts selling a different type of product. Some example of brand extension are: Apple: from personal computers into MP3 players.
What is category type?
is that category is a group, often named or numbered, to which items are assigned based on similarity or defined criteria while type is a grouping based on shared characteristics; a class.
What are Swift categories?
In Swift, there are two kinds of types: named types and compound types. A named type is a type that can be given a particular name when it’s defined. Named types include classes, structures, enumerations, and protocols. For example, instances of a user-defined class named MyClass have the type MyClass .