實例屬性
first
集合的第一個元素。
聲明
var first: Self.Element? { get }
詳述
如果集合為空,則此屬性的值為 nil
。
let numbers = [10, 20, 30, 40, 50]
if let firstNumber = numbers.first {
print(firstNumber)
}
// Prints "10"
可用版本
iOS 8.0+, iPadOS 8.0+, macOS 10.10+, Mac Catalyst 13.0+, tvOS 9.0+, watchOS 2.0+
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注:本文由純淨天空篩選整理自apple.com大神的英文原創作品 LazyDropWhileSequence first。非經特殊聲明,原始代碼版權歸原作者所有,本譯文未經允許或授權,請勿轉載或複製。