Swift Fundamentals

Swift is a compiled, type-safe programming language used for Apple-platform apps, server software, command-line tools, and other systems. Its syntax makes missing values, errors, and mutable state explicit so the compiler can catch many mistakes before a program runs.

itProgramming languages

Swift Fundamentals

Swift is a compiled, general-purpose programming language. The compiler checks types, definite initialization, memory access, and many concurrency rules before producing machine code. The standard library supplies core types and protocols. Foundation adds APIs for data, dates, files, networking, and other system tasks. Swift Package Manager organizes reusable modules and their dependencies.

Swift is closely associated with apps for Apple platforms, where it works with frameworks such as SwiftUI and UIKit. The open source toolchain also runs on Linux and Windows. The same language can therefore support command-line tools, services, libraries, and embedded programs, although framework availability differs by platform.

From source to running program

A source file contains declarations and executable statements. Declarations introduce names such as constants, variables, functions, structures, classes, enumerations, and protocols. The compiler parses and type-checks these files as part of a module. It then emits an executable or a library for a target platform.

A Swift package describes products, targets, and dependencies in Package.swift. A target normally becomes a module, which forms the namespace imported by other source files. Swift Package Manager resolves compatible dependency versions, records the chosen versions, builds the target graph, and runs tests.

package → targets → modules → source files → declarations
   ↓          ↓
products   dependencies

Swift Fundamentals

Swift Fundamentals

From source to running program

Values, bindings, and types

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