seq.sum

🌀 Sequence

available when Element conforms to AdditiveArithmetic.

💾 程式： paiza.io

// 🅿️ `AdditiveArithmetic`: supports +, -, .zero.
extension Sequence where Element: AdditiveArithmetic {
    /// sum of the elements.
    /// ```
    /// [1, 2, 3, 4, 5].sum       // 15
    /// ```
    public var sum: Element { reduce(.zero, +) }
}

let sum = [1, 2, 3, 4, 5].sum       // 15

📗 參考

• Jesse ⟩ Exploring Swift’s numeric types and protocols

📘 手冊

• SwiftDoc ⟩ Numeric

• Swift ⟩ Numbers and Basic Values ⟩ Numeric Protocols ⟩ Numeric

👥 相關

• Sequence extension (where Element: AdditiveArithmetic) .