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Subjects

JAVASCRIPTHTMLCSSPYTHONSQLJAVACPPCSHARPPHPTYPESCRIPTCRUBYGOSWIFTKOTLINRUSTRBASHSCALAOBJECTIVE-CDARTPERLLUAMATLABXMLJSONMARKDOWNASSEMBLYLATEXYAMLSOLIDITYBLOCKCHAIN

Topics

Swift Basics

Introduction to SwiftSwift Development EnvironmentSwift SyntaxSwift Variables and ConstantsSwift Data TypesSwift OperatorsSwift CommentsSwift Type InferenceSwift Type SafetySwift OptionalsSwift Optional BindingSwift Tuples

Control Flow

Swift If-Else StatementsSwift Switch StatementsSwift For LoopsSwift While LoopsSwift Repeat-While LoopsSwift Break and ContinueSwift Guard StatementsSwift Defer Statements

Functions and Closures

Swift FunctionsSwift Function ParametersSwift Return ValuesSwift Variadic ParametersSwift In-Out ParametersSwift Function TypesSwift Nested FunctionsSwift ClosuresSwift Trailing ClosuresSwift Capturing Values

Collections and Enumerations

Swift ArraysSwift SetsSwift DictionariesSwift Collection OperationsSwift EnumerationsSwift Raw Value EnumerationsSwift Associated Values

Object-Oriented Programming

Swift ClassesSwift StructuresSwift PropertiesSwift MethodsSwift InheritanceSwift InitializationSwift DeinitializationSwift Access ControlSwift Type CastingSwift Nested Types

Protocols and Extensions

Swift ProtocolsSwift Protocol ConformanceSwift Protocol ExtensionsSwift DelegationSwift ExtensionsSwift Generic Protocols

Error Handling and Debugging

Swift Error HandlingSwift Do-Try-CatchSwift AssertionsSwift PreconditionsSwift Debugging Techniques

Generics

Swift Generic FunctionsSwift Generic TypesSwift Type ConstraintsSwift Associated TypesSwift Generic Where Clauses

Memory Management

Swift ARCSwift Strong Reference CyclesSwift Weak ReferencesSwift Unowned ReferencesSwift Capture Lists

Concurrency

Swift Grand Central DispatchSwift Operation QueuesSwift Async/AwaitSwift ActorsSwift Task GroupsSwift Sendable Protocol

Swift Standard Library

Swift String ManipulationSwift Number and Math OperationsSwift Date and TimeSwift Sequence and CollectionSwift Codable ProtocolSwift Result Type

Swift and Objective-C

Swift and Objective-C InteropSwift Bridging Header@objc and dynamicSwift Selector

Advanced Swift

Swift Property WrappersSwift Custom OperatorsSwift SubscriptsSwift Key PathsSwift MetatypeSwift Phantom TypesSwift Result Builders

Swift Inheritance

Inheritance is a crucial feature in Swift that allows classes to inherit properties and methods from other classes. This powerful mechanism promotes code reuse and enables the creation of hierarchical relationships between classes.

Basic Inheritance Syntax

In Swift, you can define a class that inherits from another using a colon followed by the superclass name:

class Subclass: Superclass {
    // Subclass definition
}

Overriding Methods

Subclasses can override methods inherited from their superclass. Use the override keyword to indicate that you're intentionally providing a new implementation:

class Animal {
    func makeSound() {
        print("The animal makes a sound")
    }
}

class Dog: Animal {
    override func makeSound() {
        print("The dog barks")
    }
}

Accessing Superclass Methods

To call a method from the superclass within an overridden method, use the super keyword:

class Cat: Animal {
    override func makeSound() {
        super.makeSound()
        print("The cat meows")
    }
}

Inheritance and Initialization

When working with inheritance, it's important to properly initialize all properties. Swift requires that all stored properties have an initial value by the time initialization completes. For more details on this topic, check out the guide on Swift Initialization.

Preventing Inheritance

To prevent a class from being subclassed, you can mark it as final:

final class CannotBeInherited {
    // Class implementation
}

Best Practices

  • Use inheritance to model "is-a" relationships between classes.
  • Keep your class hierarchies shallow to avoid complexity.
  • Consider using Swift Protocols and composition for more flexible designs.
  • Always use the override keyword when overriding methods or properties.

Related Concepts

To fully understand inheritance in Swift, it's beneficial to explore these related topics:

Mastering inheritance is crucial for effective object-oriented programming in Swift. It allows you to create powerful, hierarchical relationships between classes, promoting code reuse and enabling polymorphic behavior.