iOS Development UIKit Framework 1 — Questions and Answers
Question 1: Which UIKit class is the base class for all visible UI elements?
- UIView (Correct answer)
- UIControl
- UIResponder
- UIWindow
Correct answer: UIView
`UIView` is the fundamental building block for all UIKit UI elements, providing drawing, layout, and event handling.
Question 2: What is the role of UIViewController in a UIKit app?
- Manages a view hierarchy and coordinates with the app's data model (Correct answer)
- Renders graphics directly to the screen
- Handles network requests
- Stores persistent user preferences
Correct answer: Manages a view hierarchy and coordinates with the app's data model
UIViewController manages a single root view and its subviews, acting as the intermediary between the app's data and its views.
Question 3: Which UIViewController lifecycle method is called after the view is loaded into memory?
- viewDidLoad (Correct answer)
- viewWillAppear
- viewDidAppear
- loadView
Correct answer: viewDidLoad
`viewDidLoad` is called once after the view controller's view is loaded into memory, making it ideal for one-time setup.
Question 4: What does Auto Layout do in UIKit?
- Defines the size and position of views using constraint relationships (Correct answer)
- Automatically generates view code from storyboards
- Resizes images to fit their containers
- Manages view controller transitions
Correct answer: Defines the size and position of views using constraint relationships
Auto Layout uses constraints to dynamically calculate the size and position of every view in the hierarchy.
Question 5: Which UIKit class is used to display a scrollable list of items?
- UITableView (Correct answer)
- UICollectionView
- UIScrollView
- UIStackView
Correct answer: UITableView
UITableView displays data in a single-column scrollable list with rows organized into optional sections.
Question 6: What is the purpose of a UITableViewCell reuse identifier?
- To efficiently recycle cells as they scroll off screen (Correct answer)
- To uniquely identify each row's data
- To style cells with a specific color
- To register the cell class with Interface Builder
Correct answer: To efficiently recycle cells as they scroll off screen
Reuse identifiers allow UITableView to dequeue previously allocated cells instead of creating new ones, improving scroll performance.
iOS Development UIKit Framework 1
Which UIKit class is the base class for all visible UI elements?