1. // 接口名称约定以 I 开头
    2. interface IUser {
    3.   name: string
    4.   age: number
    5. }
    7. const mu: IUser = {
    8.   name: 'yingximu',
    9.   age: 18,
    10. }
    12. const ying: IUser = {
    13.   name: '沐颖汐',
    14.   age: 19,
    15. }