Table of Contents
What is a protocol Objective C?
Objective-C allows you to define protocols, which declare the methods expected to be used for a particular situation. This chapter describes the syntax to define a formal protocol, and explains how to mark a class interface as conforming to a protocol, which means that the class must implement the required methods.
What is difference between datasource and delegate?
A data source is almost identical to a delegate. The difference is in the relationship with the delegating object. Instead of being delegated control of the user interface, a data source is delegated control of data.
What are delegates in Xcode?
A delegate is an object that another class can pass messages to. In practice delegate classes have to conform to a delegate protocol.
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.
How do you write Objective-C?
Objective-C uses the same phraseology as the C language. Like in C, each line of Objective-C code must end with a semicolon. Blocks of code are written within a set of curly brackets. All basic types are the same, such as int, float, double, long and more.
What is a property in Objective-C?
Properties in Objective-C are used to store data in instances of classes. They define memory management, type, and access attributes of the values they store such as strong , weak , assign , readonly , readwrite , etc. strong , weak , assign property attributes define how memory for that property will be managed.
Why we use delegates in iOS?
Delegation provides a way for your custom object to communicate application-specific behavior to the off-the-shelf object. The programming mechanism of delegation gives objects a chance to coordinate their appearance and state with changes occurring elsewhere in a program, changes usually brought about by user actions.
Why do we use delegates in Swift?
The core purpose of the delegate pattern is to allow an object to communicate back to its owner in a decoupled way. By not requiring an object to know the concrete type of its owner, we can write code that is much easier to reuse and maintain.
What is the difference between swift and Objective-C?
As the performance of swift, it is 2.6x faster than Objective C and 8.4x faster than python. It got an encouraging syntax that make you write clean and consistent code. It provides improve readability and prevent errors….Difference between Swift and Objective C :
| S.No. | SWIFT | OBJECTIVE C |
|---|---|---|
| 05. | Swift is static type. | Objective C is dynamic type. |
How do you create a delegate in Objective C?
19 Answers 19. An Objective-C delegate is an object that has been assigned to the delegate property another object. To create one, you simply define a class that implements the delegate methods you’re interested in, and mark that class as implementing the delegate protocol. For example, suppose you have an UIWebView.
What is a delegate in Java?
A delegate is just an object that another object sends messages to when certain things happen, so that the delegate can handle app-specific details the original object wasn’t designed for. It’s a way of customizing behavior without subclassing. Student.h 1.1 Teacher’s object’s property ‘student’ will be assigned with student object.
What is a delegate in Salesforce?
Delegates are a design pattern; there is no special syntax or language support. A delegate is just an object that another object sends messages to when certain things happen, so that the delegate can handle app-specific details the original object wasn’t designed for. It’s a way of customizing behavior without subclassing.
What is the difference between subclassing and delegation?
Instead of objects controlling one another, they can have a delegate which they send (or delegate) messages to, and the delegate does whatever they do, in order to respond and act to this message, and then usually return something back to the other object. Delegation is also a better alternative to subclassing.