實例屬性
is
isEmpty
一個布爾值,指示集合是否為空。
聲明
var isEmpty: Bool { get }
詳述
當您需要檢查您的集合是否為空時,請使用isEmpty
屬性而不是檢查count
屬性是否等於零。對於不符合 RandomAccessCollection
的集合,訪問 count
屬性會遍曆集合的元素。
let horseName = "Silver"
if horseName.isEmpty {
print("My horse has no name.")
} else {
print("Hi ho, \(horseName)!")
}
// Prints "Hi ho, Silver!")
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 Substring.UnicodeScalarView isEmpty。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。