useState
- 有初始值且类型固定
const [validating, setValidating] = React.useState(false)
- 有初始值且类型可能变
const [validating, setValidating] = React.useState<boolean | string>(false)
- 无初始值
interface IUser {
id: string
name: string
age?: number
}
const [user, setUser] = React.useState<IUser>()
当前类型对象的属性属于父类型且非必须(可选)
type IChild = Partial<IParent>
当前类型为某类型对象的属性名
type IKey = keyof IUser
函数参数赋了默认值就说明是可选的,不必再加?
(errorMsg: string, k: keyof IUser = 'respMessage') => void