实例属性
is
isEmpty
一个布尔值,指示集合是否为空。
声明
var isEmpty: Bool { get }
详述
当您需要检查您的集合是否为空时,请使用isEmpty
属性而不是检查count
属性是否等于零。对于不符合 RandomAccessCollection
的集合,访问 count
属性会遍历集合的元素。
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:本文由纯净天空筛选整理自apple.com大神的英文原创作品 UnsafeMutableRawBufferPointer isEmpty。非经特殊声明,原始代码版权归原作者所有,本译文未经允许或授权,请勿转载或复制。