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JavaScript Practice Object Interaction Checking Out and Returning a Book Solution: checkOut() and returnBook() Methods

Why can't the .setDate() method chain another method?

I want this to work. But it doesn't.

let today = new Date()
        book.dueDate = today.setDate(today.getDate() + 14);

1 Answer

Steven Parker
Steven Parker
228,978 Points

You can only chain a method if it returns an object of the same type that it is called on. But setDate returns a number and not an object.

But you could do something like this instead:

book.dueDate = new Date();
book.dueDate.setDate((new Date()).getDate() + 14);

And you can skip the first line if book.dueDate is already a Date object.