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+
相關用法
- Swift UInt32.Words index(_:offsetBy:limitedBy:)用法及代碼示例
- Swift UInt32.Words indices用法及代碼示例
- Swift UInt32.Words min(by:)用法及代碼示例
- Swift UInt32.Words contains(_:)用法及代碼示例
- Swift UInt32.Words filter(_:)用法及代碼示例
- Swift UInt32.Words dropFirst(_:)用法及代碼示例
- Swift UInt32.Words contains(where:)用法及代碼示例
- Swift UInt32.Words firstIndex(where:)用法及代碼示例
- Swift UInt32.Words randomElement()用法及代碼示例
- Swift UInt32.Words allSatisfy(_:)用法及代碼示例
- Swift UInt32.Words split(maxSplits:omittingEmptySubsequences:whereSeparator:)用法及代碼示例
- Swift UInt32.Words enumerated()用法及代碼示例
- Swift UInt32.Words map(_:)用法及代碼示例
- Swift UInt32.Words randomElement(using:)用法及代碼示例
- Swift UInt32.Words split(separator:maxSplits:omittingEmptySubsequences:)用法及代碼示例
- Swift UInt32.Words suffix(_:)用法及代碼示例
- Swift UInt32.Words shuffled()用法及代碼示例
- Swift UInt32.Words compactMap(_:)用法及代碼示例
- Swift UInt32.Words lexicographicallyPrecedes(_:)用法及代碼示例
- Swift UInt32.Words max()用法及代碼示例
- Swift UInt32.Words subscript(_:)用法及代碼示例
- Swift UInt32.Words lastIndex(of:)用法及代碼示例
- Swift UInt32.Words elementsEqual(_:)用法及代碼示例
- Swift UInt32.Words dropLast(_:)用法及代碼示例
- Swift UInt32.Words first(where:)用法及代碼示例
注:本文由純淨天空篩選整理自apple.com大神的英文原創作品 UInt32.Words 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。