Generics and Optional Parameters
TypeScript introduced the concept of generics to further strengthen the code in terms of type safety. It allows to declare functions with the type of <T> and then allows the developer to use a specific type for the operation, which will then be preserved throughout.
If you try to push a number into the string array or a string into the number array it will show a compile-time error. Another cool feature of TypeScript that is not present in JavaScript is that of optional parameters. Remember how we created a Person interface. We can add optional parameters using the ? symbol to denote that it is optional. Any classes that implement the interface can choose to include or exclude this parameter.
