interface CatInfo {
    age: number,
    breed: string
}
type CatName = 'miffy'| 'boris' | 'mordred' // 字符串字面量类型
const cats: Record<CatName, CatInfo> ={
    miffy: {age: 10, breed: "Persian"},
    boris: {age:5, breed: 'Maine Coon'},
    mordred: {age: 16, breed: 'British Shorthair'}
};
cats.boris;