手摸手一起学习Typescript第七天 - 类型别名 和 交叉类型

let sum: (x: number, y: number) => number
const result = sum(1,2)
type PlusType = (x: number, y: number) => number
let sum2: PlusType
// 支持联合类型
type StrOrNumber = string | number
let result2: StrOrNumber = '123'
result2 = 123
// 字符串字面量
type Directions = 'Up' | 'Down' | 'Left' | 'Right'
let toWhere: Directions = 'Up'
复制代码

interface IName  {
  name: string
}
type IPerson = IName & { age: number }
let person: IPerson = { name: 'hello', age: 12}