Learn SWIFT with Real Code Examples

Swift allows developers to write fast, safe, and expressive code.

It uses type inference and optionals to minimize common programming errors.

Supports protocol-oriented, object-oriented, and functional programming paradigms.

Memory safety and automatic reference counting (ARC)

Error handling with try/catch

Functional programming constructs (map, filter, reduce)

Powerful standard library

Interoperability with Objective-C

Variables and constants: var and let

Data types: Int, Double, String, Bool, Array, Dictionary

Functions: named, closures, and higher-order functions

Control flow: if, switch, for, while, guard

Optionals: ? and ! for safe handling of nil values

AppDelegate.swift / SceneDelegate.swift - application lifecycle

ContentView.swift - SwiftUI main view

Models/ - data structures

Views/ - reusable UI components

Resources/ - assets, images, and storyboards

Create a project in Xcode

Design UI using SwiftUI or Interface Builder

Write code in Swift files

Use simulators or physical devices to test

Debug using Xcode debugger and instruments

Beginner: console programs and basic apps

Intermediate: SwiftUI views and state management

Advanced: complex apps with protocols and generics

Expert: concurrency, Combine, and performance optimization

Community: contributing to Swift packages or open-source frameworks

Faster and safer than Objective-C

More modern syntax and features than C/Obj-C

Optimized for Apple ecosystem

Optionals prevent null-pointer exceptions

Supports both object-oriented and functional paradigms

2014 – Swift 1.0 released

2015 – Swift 2.0 with error handling and protocol extensions

2016 – Swift 3.0 major API redesign

2017 – Swift 4.0 with Codable and improved String handling

2025 – Swift continues evolving with Swift 6+ features

Optional: type that can hold a value or nil

Struct: value type data container

Class: reference type object

Protocol: defines a blueprint of methods/properties

Closure: anonymous function or lambda