本文介绍了可以在Typescript中扩展类型吗?的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
说我有以下类型:
type Event = { name: string; dateCreated: string; type: string; }我现在想扩展这种类型,即
I now want to extend this type, i.e.
type UserEvent extends Event = { UserId: string; }这不起作用。我该怎么做?
This doesn't work. How can I do this?
推荐答案可以使用关键字 extends 仅适用于接口和类。
The keyword extends can be used for interfaces and classes only.
如果您只想声明具有其他属性的类型,则可以使用交集类型:
If you just want to declare a type that has additional properties, you can use intersection type:
type UserEvent = Event & {UserId: string}UPDATE ,现在可以有一个扩展类似对象类型的界面:
type Event = { name: string; dateCreated: string; type: string; } interface UserEvent extends Event { UserId: string; }它不起作用 - UserEvent如果要使用 extends 语法,必须声明为接口,而不是类型。
It does not work the other way round - UserEvent must be declared as interface, not a type if you want to use extends syntax.
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可以在Typescript中扩展类型吗?
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