swift - Man Page

Safe, fast, and expressive general-purpose programming language

Examples (TL;DR)


To invoke the Swift REPL (Read-Eval-Print-Loop):


To execute a Swift program:

swift program.swift <arguments>

To work with the Swift Package Manager:

swift build|package|run|test [options] <inputs>

To invoke the Swift compiler:

swiftc [options] <inputs>

A list of supported options is available through the "-help" option:

swift -help

swift build -help

swiftc -help


Swift is a general-purpose programming language built using a modern approach to safety, performance, and software design patterns.

The goal of the Swift project is to create the best available language for uses ranging from systems programming, to mobile and desktop apps, scaling up to cloud services. Most importantly, Swift is designed to make writing and maintaining correct programs easier for the developer. To achieve this goal, we believe that the most obvious way to write Swift code must also be:

Safe. The most obvious way to write code should also behave in a safe manner. Undefined behavior is the enemy of safety, and developer mistakes should be caught before software is in production. Opting for safety sometimes means Swift will feel strict, but we believe that clarity saves time in the long run.

Fast. Swift is intended as a replacement for C-based languages (C, C++, and Objective-C). As such, Swift must be comparable to those languages in performance for most tasks. Performance must also be predictable and consistent, not just fast in short bursts that require clean-up later. There are lots of languages with novel features - being fast is rare.

Expressive. Swift benefits from decades of advancement in computer science to offer syntax that is a joy to use, with modern features developers expect. But Swift is never done. We will monitor language advancements and embrace what works, continually evolving to make Swift even better.


Reporting bugs is a great way for anyone to help improve Swift. The bug tracker for Swift, an open-source project, is located at <https://bugs.swift.org>.

If a bug can be reproduced only within an Xcode project or a playground, or if the bug is associated with an Apple NDA, please file a report to Apple's Feedback Assistant at <https://feedbackassistant.apple.com> instead.

See Also

Home Page


Apple Developer Resources


Code Repositories

Swift Programming Language at <https://github.com/apple/swift>

Swift Package Manager at <https://github.com/apple/swift-package-manager>


2023-01-25 swift 5.7.3 Swift Documentation