WARNING DON’T LEAVE OUT THE DOT WHEN IT’S NEEDED [R4R page 186]

In one situation, you must use the full object-dot-message notation, even if you’re sending the message to the current self: when the method is a setter method—a method whose name ends with an equal sign. You have to do self.venue = "Town Hall" rather than venue = "Town Hall", if you want to call the method venue=. The reason is that Ruby always interprets the sequence: bareword = value as an assignment to a local variable. To call the method venue= on the current object, you need to include the explicit self. Otherwise, you’ll end up with a variable called venue and no call to the setter method.