SwiftDoc.org hosts documentation for several versions of the Swift standard library. Choose a version from the list below, or select from the drop-down list on any page of documentation. Nightly build (swift/master, 1466a5e) Swift 5.1 (Xcode 11.3.1, swiftlang-1100.0.282.1) Swift 4.2 (Xcode 10.0b1, swiftlang-1000.0.16.7) Swift 3.1 (Xcode 8.3b2, swiftlang-802.0.31.3) Swift 3.0 (Xcode 8.2, swiftlang-800.0.63) Swift 2.2 (Xcode 7.3, swiftlang-703.0.18.1) Swift 2.1 (Xcode 7.2, swiftlang-700.1.101.19) Swift 1.2 (Xcode 6.3+, swiftlang-602.0.49.6)