Mastering TypeScript 3 - Third Edition

The Person class

To simplify our code, we will create an abstract base class to hold all code that is common to infants, children, and adults. Again, abstract classes can never be instantiated, and, as such, are designed to be derived from. We will call this class Person, as follows:

abstract class Person implements IPerson { Category: PersonCategory; private DateOfBirth: Date; constructor(dateOfBirth: Date) { this.DateOfBirth = dateOfBirth; this.Category = PersonCategory.Undefined; } abstract canSignContracts(): boolean printDetails() : void { console.log(`Person : `); console.log(`Date of Birth : ` + `${this.DateOfBirth.toDateString()}`); console.log(`Category : ` + `${PersonCategory[this.Category]}`); console.log(`Can sign : ` + `${this.canSignContracts()}`); ...