Quick Answer: What Is Difference Between Delegate And Datasource In IOS?

What is data source and delegate in iOS?


What is difference between protocol and delegate in iOS?

What class does UITableView inherit from?

The UITableView Class Hierarchy The UITableView class is a subclass of UIScrollView, which in turn inherits from UIView, UIResponder, and ultimately NSObject, as shown in Figure 2-2.

What is UITableViewDataSource?

UITableViewDataSource is a protocol you implement to provide data for your UITableView . So, with UITableViewDelagate protocol you will be able to response to events like: selection on your rows, editing and several others. With UITableViewDataSource protocol you will be able to feed data into your table.

Is a delegate?

A delegate is a person selected to represent a group of people in some political assembly of the United States. There are various types of delegates elected to different political bodies.

What do presidential delegates do?

Delegate: A person authorized to represent others as an elected representative to a political party conference. … Primary: An election where voters select candidates for an upcoming general election. Winning candidates will have delegates sent to the national party convention as their party’s U.S. presidential nominee.

What is a delegate at large?

At-large is a description for members of a governing body who are elected or appointed to represent a whole membership or population (notably a city, county, state, province, nation, club or association), rather than a subset.

How do you use data to pass a delegate?

First: Check if the delegate is not nil. If the delegate is nil then that means its not yet authorized to use this function to send data. Hence, its very important to first check nil for the delegate variable. Second: Check if there is some data entered in the TextField.

How do I create a delegate in swift 5?

Implement A Custom Delegate A clean approach to doing so is to first define a class or struct , and then extend the class or struct to adhere to the delegate. // Define a class ActionController class ActionController { // Define variables that match the delegate // protocol definition var state: ViewState = .

What is protocol in Swift?

A protocol defines a blueprint of methods, properties, and other requirements that suit a particular task or piece of functionality. The protocol can then be adopted by a class, structure, or enumeration to provide an actual implementation of those requirements.

What is datasource in iOS Swift?

Why delegates are weak in Swift?

With using lazy keyword we are not initializing delegate which means there is no memory leak right now. Let’s break that. Object will be created and there will be memory leak. … Therefore, if the object conforming to the protocol needs to be stored in a weak property then the protocol must be a class-only protocol.

Why do we use delegates in Swift?

Delegation is used for everything from handling table view events using UITableViewDelegate , to modifying cache behavior using NSCacheDelegate . The core purpose of the delegate pattern is to allow an object to communicate back to its owner in a decoupled way.

Why delegates are weak iOS?

The reason that objects weakly retain their delegates is to avoid retain cycles. Imagine the following scenario: object a creates b and retains it, then sets itself as b ‘s delegate. a is released by its owner, leaving a retain cycle containing a and b . This is actually a very common scenario.

What is a delegate iOS?

What is a delegate to the House of Representatives?

Non-voting members of the United States House of Representatives (called either delegates or resident commissioner, in the case of Puerto Rico) are representatives of their territory in the House of Representatives, who do not have a right to vote on proposed legislation in the full House but nevertheless have floor …

WHAT IS protocols in iOS?

In iOS development, a protocol is a set of methods and properties that encapsulates a unit of functionality. The protocol doesn’t actually contain any of the implementation for these things; it merely defines the required elements.

What is a delegate in swift programming?

Delegation is a design pattern that enables a class to hand off (or “delegate”) some of its responsibilities to an instance of another class.

How do I pass data between two view controllers?

You can pass data between view controllers in Swift in 6 ways:By using an instance property (A → B)By using segues with Storyboards.By using instance properties and functions (A ← B)By using the delegation pattern.By using a closure or completion handler.By using NotificationCenter and the Observer pattern.Feb 14, 2021

What is Xcode delegate?

A delegate is an object that acts on behalf of, or in coordination with, another object when that object encounters an event in a program. The delegating object is often a responder object—that is, an object inheriting from NSResponder in AppKit or UIResponder in UIKit—that is responding to a user event.

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