Swift Naming Conventions: Apple's Official API Design Guidelines

4 min read

Swift follows Apple's API Design Guidelines, which emphasize clarity, brevity, and consistency.

Convention Table

ItemConventionExample
Variables/PropertiescamelCaseuserName, isEnabled
Functions/MethodscamelCasemakeNoise()
Types (class/struct/enum)PascalCaseUserProfile
ProtocolsPascalCaseCodable, Equatable
Enum casescamelCase.loading, .success

Key Principles

  • Name methods for their side effects: mutating = verb (sort()), non-mutating = noun (sorted())
  • Boolean properties read as assertions: isEmpty, canBecomeFirstResponder
  • Factory methods begin with make: makeIterator()

Convert

camelCase, PascalCase. Hub.