Clapingo IOS Developer Interview Questions and Answers for Freshers

Struct is value type while Class is reference type in Swift. Structs are passed by value while Classes are passed by reference.

• Structs are ideal for small data types like coordinates, colors, etc.

• Classes are ideal for larger data types like view controllers, network managers, etc.

• Structs are immutable by default while Classes are mutable.

• Structs cannot inherit from other types while Classes can.

• Structs are stack alloca...read more

Classes and structures are both used to define custom data types, but they have some key differences.

• Classes are reference types, while structures are value types.

• Classes support inheritance, while structures do not.

• Classes have deinitializers, while structures do not.

• Classes have reference counting for memory management, while structures do not.

• Classes can have optional property types, while structures cannot.

Retain cycle is a memory management issue where objects reference each other and cannot be released. It can be avoided by using weak or unowned references.

• Retain cycle occurs when two or more objects hold strong references to each other.

• To avoid retain cycle, use weak or unowned references instead of strong references.

• Weak references do not increase the reference count of an object and automatically become nil when the...read more

Opinion binding is a legal doctrine that requires judges to follow the decisions of higher courts in similar cases.

• Opinion binding is also known as stare decisis.

• It helps to ensure consistency and predictability in the legal system.

• For example, if a higher court has already ruled that a certain law is unconstitutional, lower courts must follow that ruling in similar cases.

• Opinion binding can be controversial, as it can...read more

GCD and Operation Queues are both used for concurrent programming in iOS, but differ in their approach.

• GCD is a C-based API that uses a thread pool model for concurrency.

• Operation Queues are built on top of GCD and provide a higher-level abstraction for concurrency.

• GCD is best for simple, lightweight tasks, while Operation Queues are better for more complex tasks with dependencies.

• GCD uses blocks for task execution, wh...read more

The life cycle of iOS applications refers to the stages an app goes through from launch to termination.

• The app is launched by the user or system

• The app enters the foreground and becomes active

• The app can be sent to the background or suspended

• The app can be terminated by the user or system

• The app can be resumed from the background or suspended state

• The app can receive memory warnings and handle them appropriately

The UIViewController life cycle consists of several stages that occur when the view controller is loaded and unloaded.

• viewDidLoad() - called when the view controller's view is loaded into memory

• viewWillAppear() - called just before the view appears on the screen

• viewDidAppear() - called just after the view appears on the screen

• viewWillDisappear() - called just before the view disappears from the screen

• viewDidDisappear()...read more