Join Scott Gardner for an in-depth discussion in this video Associated types, part of Swift 3 Essential Training: Beyond the Basics.
- [Instructor] Protocols can define associated types,…which are type aliases for use in defining requirements…that the adopting type will define.…I'll start off by defining a protocol, HasMiddle.…I wanted adopting types to define…an associated type alias item.…So I'll define that associated type alias…by writing associatedtype Item.…If you're coming from Swift 2,…you might've been familiar with writing typealias here.…This was changed in Swift 2.2,…to use the new associated type keyword here, instead,…in order to clarify that this is an associated type…to be defined by adopting types,…not a typealias actually being…defined in the protocol itself.…
Next, I'll require two methods.…Middle will return an optional of type Item,…and middleArray an optional array of Item.…This covers returning the appropriate type…from Arrays with odd and even counts of elements.…Or returning nil for an empty Array.…I'll extend an array to adopt and conform to HasMiddle.…First, I'll define the typealias Item…equal to an array's Element type.…
- Adding source files, resources, links, and literals
- Adding pages to a playground
- Using overflow operators and bitwise operators
- Using ranges with strings
- Creating complex sequences
- Chaining higher-order functions
- Defining lazy properties
- Using failable initializers
- Mutating methods
- Working with singletons
- Nesting function types
- Creating error types and recursive enumerations
- Extending concrete types
- Referencing selectors and key paths
- Working with protocol-oriented programming
- Defining class-only protocols and optional protocols
- Using option sets, type checking, and casting operators
Skill Level Intermediate
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Distributing Your iOS App for Testing with TestFlightwith Ron Buencamino35m 10s Intermediate
iOS App Development: Test-Driven Developmentwith Harrison Ferrone2h 14m Intermediate
3. Strings and Characters
4. Sequences and Collections
5. Control Flow
6. Value and Reference Types
9. Access Control
Understand access control3m 47s
Next steps1m 2s
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