interface

partial

  1. interface a {
  2.     name:string;
  3.     age:number
  4. }
  6. type b = Partial<a>
  8. b为
  9. type b = {
  10.     name?: string | undefined;
  11.     age?: number | undefined;
  12. }

required
readonly

pick

  1. interface a {
  2.     name?:string;
  3.     age?:number;
  4.     id:number;
  5. }
  7. type c = Pick<a,'name'>
  8.   //
  9.   type c = {
  10.     name?: string | undefined;
  11. }

omit

  1. interface a {
  2.     name?:string;
  3.     age?:number;
  4.     id:number;
  5. }
  7. type c = Omit<a,'name'>
  8.  // 
  9.   type c = {
  10.     age?: number | undefined;
  11.     id: number;
  12. }

record

定义对象的键值对类型

  1. interface PageInfo {
  2.   title: string;
  3. }
  5. type Page = "home" | "about" | "contact";
  7. const nav: Record<Page, PageInfo> = {
  8.   about: { title: "about" },
  9.   contact: { title: "contact" },
  10.   home: { title: "home" },
  11. };

type

Exclude — 从T中剔除可以赋值给U的类型。

  1. type a = Number | String | Boolean
  3. type b = Exclude<a,Number>
  5. b:
  6. type b = String | Boolean

Extract — 提取T中可以赋值给U的类型。
NonNullable — 从T中剔除null和undefined。
ReturnType — 获取函数返回值类型。
InstanceType — 获取构造函数类型的实例类型。