Environment and syntax

How to Install Swift on macOS

To set up Swift on macOS, you need Xcode, Apple's official Integrated Development Environment (IDE) for building applications across all Apple platforms. Xcode comes with a complete set of tools, including a Swift compiler, debugger, and simulator, allowing developers to write, test, and deploy Swift applications efficiently. br
Xcode supports multiple programming languages, including Swift, Objective-C, Java, Python, C++, and C, making it a versatile development tool.

Steps to Install Xcode on macOS

1. Open the Mac App Store – Launch the App Store on your Mac.

2. Search for Xcode – Type “Xcode” in the search bar and locate Apple’s official IDE.

3. Download and Install – Click “Get” and then “Install” to begin downloading Xcode.

installing Xcode

4. Wait for Installation – The installation process may take some time, depending on your internet speed.

5. Once installed, find Xcode in the Applications folder or use Spotlight (Cmd + Space) → Type "Xcode" → Press Enter.


6.Launch Xcode – Once installed, open Xcode, accept the license agreement, and allow it to install additional components if required.

Alternatively, you can download Xcode directly from Apple’s official website: Swift.org

After installing Xcode, Swift is automatically available on your Mac, and you can start coding using Xcode’s playgrounds or the Terminal Swift REPL.

7. Click "Create a new Xcode project"

new project

8. Select a location to save your playground and click Create.

select location

9. Write Swift Code

writting code

10. Run the Code

How to Install Swift on Windows

Although Swift is primarily designed for macOS, it can be installed on Windows using third-party tools. Follow these steps to set up Swift on your Windows system:

Step 1: Download Swift for Windows

  • Visit the official Swift website: Swift.org
  • Download the latest Swift for Windows package.

Step 2: Install Dependencies

Before installing Swift, ensure you have the necessary dependencies:

  • Visual Studio – Install the Visual Studio 2019/2022 with the "Desktop development with C++" workload.
  • Windows Subsystem for Linux (WSL) – Some Swift features may require WSL for better compatibility.
  • LLVM (Clang for Windows) – Swift requires LLVM to compile and run properly.

Step 4: Set Up Environment Variables

  • Open Control Panel > System > Advanced System Settings
  • Click on Environment Variables
  • Under System Variables, locate Path, and click Edit
  • Add the Swift installation path (e.g., C:\Swift\bin)
  • Click OK and restart your computer to apply changes

Step 5: Verify the Installation

Open Command Prompt (cmd) or PowerShell

Type:

Swift --version

If Swift is installed correctly, it will display the installed version.

Now, you can start coding with Swift using Command Prompt, PowerShell, or Swift Playgrounds on Windows!

Swift - Basic Syntax

Once Swift is successfully installed, running swift --version in the terminal will confirm the installed version. Swift is a modern, expressive, and easy-to-use programming language designed for building applications across Apple’s ecosystem. It supports both object-oriented and functional programming paradigms, making it a versatile and powerful choice for developers.

Basic Swift Program

Here’s a simple Swift program to display "Hello, World!"

/* My first Swift program */
var myString = "Hello, World!"
print(myString)

Following is the output of the above program −

Hello, World!

This example demonstrates Swift’s clear and concise syntax, which makes it easy to read, write, and maintain.

Importing Libraries

Swift allows importing Objective-C frameworks, C libraries, or Swift modules directly into your program using the import statement.

Syntax:

import frameworkName or LibraryName

Example

import Foundation

Here, the Foundation framework is imported, which provides essential data types and functions.

Swift Tokens

A token is the smallest element of a Swift program, used to build the language structure. Swift programs consist of various tokens, such as:

  • ✔ Keywords (e.g., var, import)
  • ✔ Identifiers (e.g., variable names)
  • ✔ Constants (e.g., 34, "Hello")
  • ✔ String literals (e.g., "Swift Programming")
  • ✔ Symbols (e.g., +, =, {})

Example of Tokens in Swift:

import Foundation
var muNumber = 30
print(myNumber)

Output

30

In this example, import, Foundation, var, myNumber, print are all tokens in Swift.

Semicolons in Swift

Swift does not require semicolons (;) at the end of each statement, unlike C or Java. However, if multiple statements are written on the same line, a semicolon is required to separate them.

Example:

var x = 10 ; var y = 20 ; print(x + y)

Output

30

If semicolons are not used between statements in the same line, the compiler will generate a syntax error.

Swift - Reserved Keywords

Reserved keywords in Swift are predefined words that hold special meanings and functions within the language. Since they are reserved, they cannot be used as variable names, constants, or identifiers—unless they are escaped with backticks ( ).

Example:

var class = "Swift" // ❌ Error: 'class' is a reserved keyword
var `class` = "Swift" // ✅ Valid usage with backticks
print (`class`) // Output: Swift

These reserved keywords define the structure, behavior, and functionality of Swift programs.

List of Reserved Keywords in Swift



Swift reserves the following keywords:



1. Keywords Used in Declarations

  • associatedtype
  • class
  • deinit
  • enum
  • extension
  • func
  • import
  • init
  • inout
  • let
  • operator
  • protocol
  • static
  • struct
  • subscript
  • typealias
  • var

2. Keywords Used in Statements

  • break
  • case
  • continue
  • default
  • defer
  • do
  • else
  • fallthrough
  • for
  • guard
  • if
  • in
  • repeat
  • return
  • switch
  • where
  • while

3. Keywords for Expressions and Types

  • as
  • Any
  • catch
  • false
  • is
  • nil
  • rethrows
  • super
  • self
  • Self
  • throw
  • throws
  • true
  • try
  • Type

4. Keywords Used in Patterns

  • _
  • #available
  • #file
  • #fileID
  • #filePath
  • #function
  • #line
  • #column
  • #dsohandle

5. Keywords for Contextual Use

These are not strictly reserved but have special meaning in certain contexts:

  • actor
  • async
  • await
  • final
  • lazy
  • mutating
  • nonmutating
  • optional
  • override
  • required
  • throws
  • weak
  • unowned

Swift - Whitespace and Literals

Whitespace in Swift

Whitespace in Swift refers to spaces, tabs, newlines, and comments used to improve readability and separate different elements in a statement.

Example:

var age // ✅ Correct (space between 'var' and 'age')

Without whitespace, the Swift compiler would not recognize varage as two separate tokens.

However, some parts of a statement do not require whitespace:

// ✅ Correct: No whitespace needed around `=`
var fruits = apples + oranges

But for better readability, always use equal spaces around operators:

// ✅ Correct: No whitespace needed around `=`
var fruits =apples+oranges // ❌ Incorrect (no spaces)
var fruits = apples + oranges // ✅ Correct