typescript类型体操记录贴(三)Readonly

李恒道

地址
https://github.com/type-challenges/type-challenges/blob/main/questions/00007-easy-readonly/README.md

Readonly

Implement the built-in Readonly<T> generic without using it.

Constructs a type with all properties of T set to readonly, meaning the properties of the constructed type cannot be reassigned.

For example:

实现内置Readonly泛型而不使用他
构建一个类型将T的所有属性设置成只读，意味着所有属性之恩给你构建类型不能去重新设置
例如

interface Todo {
  title: string
  description: string
}

const todo: MyReadonly<Todo> = {
  title: "Hey",
  description: "foobar"
}

todo.title = "Hello" // Error: cannot reassign a readonly property
todo.description = "barFoo" // Error: cannot reassign a readonly property

这题跟二差不多
基本白给题
直接K in keyof T
遍历T的所有属性，然后加一个readonly即可
上代码

type MyReadonly<T> = {
  readonly [K in keyof T]:T[K]
}

搞定