Note·TypeScript 中 interface 和 type 区别

// interface
interface User {
  name: string
  age: number
}

interface SetUser {
  (name: string, age: number): void
}

// type
type User = {
  name: string
  age: number
}

type SetUser = (name: string, age: number) => void

// interface extends interface
interface Name {
  name: string;
}
interface User extends Name {
  age: number;
}

// type extends type
type Name = {
  name: string,
}
type User = Name & { age: number }

// interface extends type
type Name = {
  name: string,
}
interface User extends Name {
  age: number;
}

// type extends interface
interface Name {
  name: string;
}
type User = Name & {
  age: number,
}

// 基本类型别名
type Name = string

// 联合类型
interface Dog {
    wong();
}
interface Cat {
    miao();
}

type Pet = Dog | Cat

// 具体定义数组每个位置的类型
type PetList = [Dog, Pet]

// 当你想获取一个变量的类型时，使用 typeof
let div = document.createElement('div')
type B = typeof div

type StringOrNumber = string | number
type Text = string | { text: string }
type NameLookup = Dictionary<string, Person>
type Callback<T> = (data: T) => void
type Pair<T> = [T, T]
type Coordinates = Pair<number>
type Tree<T> = T | { left: Tree<T>, right: Tree<T> }

interface User {
  name: string
  age: number
}

interface User {
  sex: string
}

/*
User 接口为 {
  name: string
  age: number
  sex: string
}
*/