本文所有东西尽可在 typescript 官网文档寻找,但是深浅不一

高级类型

lib 库中的五个高级类型
以下所有例子皆以 person 为例

interface Person {    name: string;    age?: number;}

Partial

源码:

type Partial<T> = {    [P in keyof T]?: T[P];};

实例:

type person2 = Partial<Person>;// person2 === {name?: string; age?: number}

Required

源码:

type Required<T> = {    [P in keyof T]-?: T[P];};

实例:

type person3 = Required<Person>;// person3 === {name: string; age: number}

Readonly

源码:

type Readonly<T> = {    readonly [P in keyof T]: T[P];};

实例:

type person4 = Readonly<Person>;// person4 === {//        readonly name: string;//        readonly age?: number;//  }

Pick

源码:

type Pick<T, K extends keyof T> = {    [P in K]: T[P];};

实例:

type person5 = Pick<Person, "name">;// person5 === {name: string}

Record

源码:

type Record<K extends keyof any, T> = {    [P in K]: T;};

实例:

type person6 = Record<'name' | 'age', string>// person6 === {name: string; age: string}

条件类型

关于条件类型,官网上说的很详细了,我就直接拿过来

type T00 = Exclude<"a" | "b" | "c" | "d", "a" | "c" | "f">;  // "b" | "d"type T01 = Extract<"a" | "b" | "c" | "d", "a" | "c" | "f">;  // "a" | "c"type T02 = Exclude<string | number | (() => void), Function>;  // string | numbertype T03 = Extract<string | number | (() => void), Function>;  // () => voidtype T04 = NonNullable<string | number | undefined>;  // string | numbertype T05 = NonNullable<(() => string) | string[] | null | undefined>;  // (() => string) | string[]function f1(s: string) {    return { a: 1, b: s };}class C {    x = 0;    y = 0;}type T10 = ReturnType<() => string>;  // stringtype T11 = ReturnType<(s: string) => void>;  // voidtype T12 = ReturnType<(<T>() => T)>;  // {}type T13 = ReturnType<(<T extends U, U extends number[]>() => T)>;  // number[]type T14 = ReturnType<typeof f1>;  // { a: number, b: string }type T15 = ReturnType<any>;  // anytype T16 = ReturnType<never>;  // anytype T17 = ReturnType<string>;  // Errortype T18 = ReturnType<Function>;  // Errortype T20 = InstanceType<typeof C>;  // Ctype T21 = InstanceType<any>;  // anytype T22 = InstanceType<never>;  // anytype T23 = InstanceType<string>;  // Errortype T24 = InstanceType<Function>;  // Error

高级类型与条件类型就这些,如果能够掌握他们,你就能在 ts 的海洋中任意遨游了