Introduction to Swift and Playgrounds
Learn about the origin of Swift and some of its basic syntax.

Constants, Variables, and Data Types
Learn how to define constants for values that don’t change and variables for values that do. Learn the data types that are included in Swift and how they can help you write better code.

Operators
Learn about some of the operators in the Swift language, including basic math operators.

Control Flow
Learn how to use logical operators in Swift to check conditions; learn how to use control flow statements.

Strings
Learn how to create and store text using the string type. You'll learn a variety of string methods that allow you to compare two strings, access specific characters within a string, and insert and remove values.

Functions
Learn how to declare functions with different parameters and return types.

Structures
Learn how to create structures in Swift.

Classes
Learn what makes classes different from structures and when to use classes instead of structures. Also learn about inheritance, superclasses, and subclasses.

Optionals
Learn to use “optionals” to properly handle situations when data may or may not exist.

Collections
Learn about the various collection types available in Swift and how to choose the appropriate one for your program.

Loops
Learn how to create loops in Swift, control the conditions for looping, and specify when to stop.

Type Casting
Learn why some data can be expressed using only a broader type, and how you can test for specific kinds of data before using it.

Guard
Learn to use guard statements to better manage control flow.

Scope
Learn to write nicely structured code that's easy to read. You'll do this by properly scoping your constants and variables.

Enumerations
Learn when enumerations are commonly used, how to define an enumeration, and how to work with enumerations using switch statements.

Protocols
Learn what protocols are, when to use them, and how to write your own. Learn how to enable objects to communicate with each other and how to extend protocols to provide shared functionality across multiple types.

Closures
Learn about closures, how to define them, how to use them as function arguments, and how to use some of the common functions that take closures as arguments.

Extensions
Learn how to define an extension, as well as how and why to use extensions.