Swift 101: Definition, Features, and How To Start?

In this article, we will explore the knowledge of Swift programming. Specifically, we will start from the basics and gradually delve into the usage.

Whether you’re interested in building mobile or macOS apps, Swift 101 will give you a solid basis to start your coding journey.

Read on for more!

What Is Swift?

Swift is a powerful and intuitive language created by Apple. It’s fast and secure for macOS, iOS, watchOS, and tvOS apps.

Besides, it has the best features of modern languages for clean and efficient codes. Also, it supports both functional and OOP paradigms. Hence, it offers features like type inference, options, and pattern matching.

How Does Swift Work?

Swift is a compiled language. In other words, it goes through a process called compilation before executing.

This process involves translating human-readable Swift code into a lower-level representation called LLVM IR, which is platform-independent.

Then you must develop this code to improve performance and generate efficient machine code specific to your task. You can perform this procedure with your computer’s processor.

Features Of Swift

After getting a basic understanding of this language, note the following features to work with it better!

1. Readability And Brevity

Swift adopts a clear and intuitive syntax that resembles the natural English language, reducing the cognitive load required to understand and write code.

2. Type Safety

Swift is a type-safe language which means it enforces strong type-checking during compilation.

This feature ensures that variables and expressions have compatible types, reducing the chance of runtime errors and improving code reliability.

Besides, it needs explicit type annotations for variables and function parameters. Thus, it enhances code clarity and helps understand the expected data types.

Hence, type safety helps detect errors at compile time, promotes safer codes, and gives devs confidence in the correctness of their tasks.

3. Optionals

With this language, you can declare variables as optional by adding a question mark “?” to their type – Indicating that the variable can hold a value or be nil.

Besides, it explicitly unwraps options to access their underlying values. Hence, it ensures you know the possibility of nil and handles it.

4. Automatic Memory Management

Swift uses ARC for automatic memory management. The tool automatically monitors and manages memory allocation and release for objects.

Besides, it keeps track of the number of references to an object. Also, it releases memory when there are no more references to that object, preventing memory leaks.

Hence, you don’t need to allocate or free memory because ARC handles it seamlessly.

Also, ARC works well behind the scenes, ensuring managing memory without needing explicit memory control code.

5. Library

The Swift Standard Library is a vast collection of reusable code included. It offers a variety of functions, including:

  • Types of data
  • Algorithm
  • Utilities

Besides, it offers vital parts like collections (arrays, sets, dictionaries), strings, numeric types, file handling, networking, concurrency primitives, etc.

Also, it has powerful features such as generic drugs, protocols, and extensions, allowing you to write code. Thus, you have access to a rich set of tools that enable the creation of the best apps.

6. Closures

Closures are independent blocks of code that can capture and store references to variables and constants from their surrounding context. They allow you to pack functions and convert them to first-class values.

Besides, they provide a concise syntax for defining and using anonymous functions.

7. Protocols And Generics

Swift developers

Protocols define a blueprint of the methods, properties, and needs that codes can follow. Hence, they facilitate code extensibility and modularity.

On the other hand, Generics offers a way to write reusable code that can work with many data types. They allow functions, structs, and classes to be parameterized by type, helping create flexible codes.

Together they provide the basis for building safe, reusable, and modular code.

8. Error Handling

Error handling offers a robust mechanism for dealing with and propagating errors.

Swift has a unified method of error handling through the use of the “try,” “catch,” and “throw” keywords.

Errors are defined by types that conform to the “Error” protocol, allowing for custom error types. With the “try” keyword, you can throw errors from a function or method and catch and handle them using “catch” blocks.

This feature allows for graceful recovery from errors or controlled propagation to higher-level error handlers.

9. Playgrounds

Playgrounds provide a lightweight environment for testing, prototyping, and learning. This feature can help you write and execute code in real time, seeing the results immediately.

Besides, they have a live view that shows the output and visualizes the code. Hence, they become ideal for:

  • Testing algorithms
  • Try new concepts
  • Build interactive experiences

Moreover, they support multimedia, such as images, videos, and interactive elements. Also, they foster collaboration and iterative development by providing playground sharing.

10. Interoperability

Swift allows devs to merge existing code bases and leverage external libraries.

Swift’s “bridge” feature can help you work with Objective-C code, allowing for smooth collaboration between Swift and Objective-C. Also, it supports C and C++ code through direct import and compatibility with their data types.

Besides, you can use it with languages like Python and Ruby thanks to various tools.

This feature opens up many options, allowing you to leverage existing code, use platform-specific features, and create hybrid solutions.

Getting Started with Swift

This section will walk you through some basics when working with Swift. These tutorials will come in handy if you’re a beginner!

1. Install Xcode

You have to install Xcode first:

1/ Open the App Store on your macOS device.

2/ Search for “Xcode” in the search bar.

3/ Click on the Xcode app in the search results.

4/ Click the “Get” or “Download” button.

5/ Enter your Apple ID credentials if prompted.

Once done, Xcode will be in the “Applications” folder on your Mac.

2. Create A New Project

The following actions will help you create a new project:

1/ Open Xcode.

2/ Click on “Create a new Xcode project” or select “File” >>> “New” >>> “Project” from the menu.

3/ Choose a template for your project, such as “iOS App” or “macOS App.”

4/ Fill in the necessary details, such as the project name, organization identifier, and language.

5/ Select the location where you want to save the project.

6/ Click “Next” and configure any additional settings as needed.

7/ Finally, click “Create” to generate the new project structure in Xcode.

3. Edit The View Controller

If you want to adjust The View Controller, follow these steps:

1/ Select the “Main.storyboard” file from the Navigator pane on the left. This file represents the controller scene view, which simulates the phone display for your app.

In the view controller scene, you can add, remove, or modify UI elements by selecting them from the Object Library.

2/ To add a button, select the “Button” option from the Object Library and drag it onto the view controller.

3/ Customize the button by double-clicking and changing the text or other properties.

4/ Save your changes and run the app to see the updated view controller with the added button.

4. Write Swift Code

Finally, write your first lines of code with this tutorial:

1/ Open the selected view controller in the Assistant Editor. Click the button in the top right corner to open this editor. Here, you can edit the code related to the view controller.

3/ Locate the function “viewDidLoad(),” which executes when the view controller loads on the device.

4/ Add your code snippet, such as a “hello world” message, at the bottom of the “viewDidLoad()” function.

Note that you don’t need to include semicolons at the end of statements, although you can if you prefer.

5/ Customize the message to your liking, but avoid modifying other parts of the code.

Save your changes and run the app to see your code executed when the view controller loads.


This post provides a detailed overview of Swift language, its defining features, and how to get started. Its clean syntax makes it the best choice for beginners and skilled devs.

By learning Swift, you open up chances to create innovative apps for iPhone, iPad, Mac, Apple Watch, and Apple TV.

So embrace the elegance and power of Swift! Happy coding!