🅿️protocol

🚧 施工中

Swift ⟩ type ⟩ category ⟩ protocol

A set of requirements, such as methods and properties, that can be adopted (or followed) by a type, such as a class, structure, or enumeration.

When a type adopts a protocol, it provides its own implementation of the protocol requirements, and is said to conform to that protocol.

🇹🇼 中文稱為「規範」或「協定」。

🔴 主題

• protocol inheritance

• protocol requirements

• protocol hierarchy

• Protocol Extensions

• generic protocol

• Conditional Conformance

• Combining Protocols

• Typecasting with Protocols

• ⚖️ some╱any╱generics

👥 相關

• protocol is a declaration.

⭐️ 重點

Protocol Requirements:

• methods

• initializers

• associated types

• properties

• inherited protocols

Any is an empty protocol and everything implicitly conforms to this protocol. 👉 AppVenture.me

💈範例

// Some code
protocol SomeProtocol {

    // -----------------------------
    //     Property Requirements
    // -----------------------------
    // • can be stored/computed property
    
    // ⭐ gettable
    // can’t be fulfilled by a constant stored property 
    // or a read-only computed property.
    var mustBeSettable: Int { get set }
    
    // ⭐ settable
    // satisfied by any kind of property
    var doesNotNeedToBeSettable: Int { get }
    
    // ⭐ type property
    static var typeProperty: Int { get set }
    
    // -----------------------------
    //     Method Requirements
    // -----------------------------
    
    func method() -> Double         // ⭐ instance method
    static func typeMethod()        // ⭐ type method
    mutating func toggle()          // ⭐ mutating method
    
    // -----------------------------
    //     Init Requirements
    // -----------------------------
    
    init(someParameter: Int)
}

📗 參考

• Paul ⟩ Swift Protocols: Tips and Tricks

• Sundell ⟩

  • The different categories of Swift protocols

  • Why can’t certain protocols, like Equatable and Hashable, be referenced directly?

• 5 Stars ⟩ Every SwiftUI protocol explained

• Khawer ⟩ When and how to use the Equatable and Identifiable protocols in Swift

• weak self podcast ⟩ 2: Swift API 設計之原來我不會用 protocol

📘 手冊

• Swift ⟩ Protocols