Swift Language: Basics Guide For Beginners

Swift is a powerful and intuitive programming language for iOS, macOS, watchOS, tvOS, and more.

Writing Swift code is interactive and fun, the syntax is concise yet expressive, and Swift includes love for developers with modern features.

Swift code is design-safe, yet it also produces lightning-fast software.

Swift combines the best of modern language thinking with wisdom from the wider Apple engineering culture and the varied contributions from its open-source community.

The compiler is optimized for efficiency and the language is optimized for growth, without compromising either.

Swift 5 Language

Swift 5 makes the release of your applications dramatically simpler. Because the Swift runtime is now integrated into iOS, macOS, tvOS, and watchOS, your app no longer requires to share this library for the latest OS versions.

Users who download from the App Store an app constructed with Swift will get a lower app and a quicker download.

Swift describes big classes of prevalent programming mistakes by adopting modern programming patterns:

Variables are always initialized before use.
Array indices are checked for mistakes that are out-of-bound.
Integers will be inspected for overflow.
Optional guarantees explicit handling of nil values.
Memory is automatically administered.
Error handling enables a controlled recovery from unexpected failures.
Swift code is compiled and optimized to make the most of contemporary hardware.
The syntax and standard libraries were intended based on the guiding principle that the highest performance should also be the apparent way to write your code.
Its combination of safety and velocity makes Swift an outstanding option for everything from "Hello World!" to a whole operating system.

Swift combines powerful type inference and pattern matching with a contemporary, lightweight syntax that allows complicated concepts to be expressed straightforwardly and concisely. As a result, code is not only simpler to write but also easier to read and retain.

Advantages of Swift

Swift is open-source and simple to know.
Swift is quick, secure, expressive.
Swift is the future of the growth of Apple.
Swift is prepared for the company.
Swift is accessible and familiar (Swift programmers can add C and C++ code into Swift apps).

Disadvantages of Swift

The language is still quite young and the pool of talent is restricted.
Lack of assistance for previous versions of iOS.
Poor interoperability with third-party instruments and IDEs.
Swift is regarded as a "moving target" as it is a fresh language and there are few swift programmers.

Features of Swift Language

Swift has many more features to make your code more expressive:

Generics that are powerful and simple to use.
Protocol extensions that make writing generic code even easier.
First-class functions and a lightweight closure syntax.
Fast and concise iteration over a range or collection.
Tuples and multiple returns values.
Structs that support methods, extensions, and protocols.
Enums can have payloads and support pattern matching.
Functional programming patterns, e.g., map and filter.
Native error handling using try/catch/throw.

1. Designed for Safety

Swift eliminates all classes of unsafe code. Variables are always initialized before use, arrays and integers are checked for overflow, and exclusive access to memory guards is enforced against many programming errors.

The syntax is tuned to make it easy to identify your intent— simple three-character keywords, for instance, define a variable (var) or a constant (let).

Swift strongly leverages value kinds, particularly for frequently used kinds such as Arrays and Dictionaries. This means that if you make a copy of something with that type, you know it won't be changed elsewhere.

2. Fast and Powerful

Swift was constructed to be quick from its earliest conception. Using the extremely high-performance LLVM compiler technology, Swift code is converted into an optimized native code that gets the most out of contemporary hardware.

Also, the syntax and standard library have been tuned to make the most evident way to write your software work best, whether it operates in the watch on your wrist or across a server cluster.

3. Easy to Learn

Swift can open doors for the coding world. It was intended to be the first programming language of anyone, whether you are still in college or exploring fresh career routes.

Apple developed a free curriculum for teachers to teach Swift both in and out of the classroom. First-time coders can download Swift Playgrounds— an iPad app that makes it interactive and enjoyable to get started with Swift code.

Aspiring app developers can access free classes to know how to construct their first Xcode applications.

Apple Stores around the globe are hosting today at Apple Coding & Apps meetings where you can get hands-on experience with Swift code.

4. Source and Binary Compatibility

With Swift 5, you don't need to modify any of your Swift 4 code to use the compiler's fresh version. On the contrary, you can begin using the new compiler and migrate at your speed, taking advantage of fresh Swift 5 characteristics, one module at a moment.

Swift 5 is now introducing binary compatibility for applications. This means that you no longer need to include Swift libraries in applications that target-present and future versions of OS, as the Swift libraries will be included in any future release of OS.

5. Open Source

Swift is developed in the open at Swift.org, with source code, a bug tracker, forums, and regular development building available to everyone.

This wide community of developers, both inside Apple as well as hundreds of outside contributors, are working together to make Swift even more incredible.

There is an even wider variety of blogs, podcasts, conferences, and meetings where community designers share their experiences of how to realize the excellent potential of Swift.

6. Cross-Platform

Swift is already supporting all Apple platforms and Linux, with community members actively working on porting to even more platforms.

The community is also working with SourceKit-LSP to incorporate Swift assistance into a wide variety of developer instruments.

We are excited to see more ways that Swift makes software safer and quicker, while also making programming more fun.

7. Swift for Server

While Swift is powering many new applications on Apple platforms, it is also being used for a fresh class of contemporary server applications.

Swift is perfect for server applications requiring runtime security, compiled performance, and a small memory footprint.

The community created the Swift Server Working Group to guide Swift's direction for creating and deploying server apps.

The first product of this attempt was SwiftNIO, a cross-platform asynchronous event-driven network application framework for servers and customers with high-performance protocols.

8. Objective-C Interoperability

Today you can develop a completely fresh application with Swift, or start using Swift code to introduce fresh characteristics and functionality in your app.

Swift code co-exists in the same project alongside your current Objective-C files, with complete access to your Objective-C API, making it simple to embrace.

Hello World program in Swift

// Hello, World! Program
import Swift
print("Hello, World!")

Output:

Hello, World!

How Swift Hello World Program Works?

// Hello, World! Program.

Any line beginning with two slashes // in Swift is a comment. The compiler totally ignores them.

Comments are designed for the individual reading the code to better comprehend the program's purpose and functionality.

import swift

Import keyword enables you to access all the symbols specified within the framework. Remember this line is now needed to use print("Hello, World!") in our program. In subsequent tutorials, you will learn more about it.

print("Hello, World!")

In Swift, the line above is called a function. More specifically, a function of printing. Printing implies "show on the screen" in quick.

The code above prints the string inside quotation marks, i.e. "Hello, World!" on the screen. You will learn more about features and how they operate in subsequent tutorials.