interface Contact { id : string ; firstName : string ; lastName : string ; picture : { url : string ; } ; phoneNumber : string ; email : string ; address : string ; } export class ContactClass implements Contact { public id : string ; constructor ( public firstName = '' , public lastName = '' , public picture = { url : '' } , public phoneNumber = '' , public email = '' , public address = '' ) { this . id = Math . random ( ) . toString ( 36 ) . substring ( 2 ) ; } } export default Contact ;