为什么Kotlin不允许对原始类型使用lateinit? [英] Why doesn't Kotlin allow to use lateinit with primitive types?

问题描述

默认情况下，使用Kotlin语言，我们必须在引入每个变量时对其进行初始化.为避免这种情况，可以使用lateinit关键字.在初始化之前引用lateinit变量会导致运行时异常.

In the Kotlin language we, by default, have to initialize each variable when it is introduced. To avoid this, the lateinit keyword can be used. Referring to a lateinit variable before it has been initialized results in a runtime exception.

lateinit不能与原始类型一起使用.为什么会这样?

lateinit can not, however, be used with the primitive types. Why is it so?

推荐答案

对于对象类型，Kotlin使用null值来标记lateinit属性尚未初始化，并在该属性为访问.

For object types, Kotlin uses the null value to mark that a lateinit property has not been initialized and to throw the appropriate exception when the property is accessed.

对于基本类型，没有这样的值，因此无法将属性标记为未初始化并提供lateinit需要提供的诊断信息. (我们可以尝试使用某种单独的标记，但是在通过反射初始化字段时不会更新该标记，这是lateinit的主要用例.)

For primitive types, there is no such value, so there is no way to mark a property as non-initialized and to provide the diagnostics that lateinit needs to provide. (We could try to use a separate marker of some kind, but that marker would not be updated when initializing the field through reflection, which is a major use case of lateinit).

因此，lateinit仅支持对象类型的属性.

Therefore, lateinit is supported for properties of object types only.

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