Inheritance and Abstract Classes

Part of the TypeScript course

You have written three classes for a payments system: CardPayment, BankTransfer and Voucher. All three have an amount, a currency and a createdAt. All three have a describe() method that prints those three fields identically. The only genuine difference between them is what happens when you call process().

So roughly seventy percent of each file is a copy of the other two. Fix a formatting bug in one describe() and you have fixed one third of the bug. ...