swift - 在 Swift 中，我们需要初始化惰性存储属性吗？

Question

在 Apple 的新 Swift 编程语言中，我遇到了以下情况:

“类和结构必须在创建该类或结构的实例时将其所有存储属性设置为适当的初始值。存储属性不能处于不确定状态。”

上述规则是否对@lazy 存储属性有效？

Answer 1

不，你没有:

A lazy stored property is a property whose initial value is not calculated until the first time it is used...

You must always declare a lazy property as a variable (with the var keyword), because its initial value may not be retrieved until after instance initialization completes...

Lazy properties are useful when the initial value for a property is dependent on outside factors whose values are not known until after an instance’s initialization is complete.

Source

基本上意味着它没有值并且在初始化后不需要立即值。