2、联合自定义类型type &

type BaseInfo ={
    name:string,
    age:number
}
type Contacts = {
    phone:string,
    address:string
}
/* 联合类型 */
type Profile = BaseInfo & Contacts;
var li:Profile ={
    name:"李四",
    age:18,
    phone:"122",
    address:"3232"
}