Ruby override method - contact class: Part 2

Hey Enrica!

I'll try to answer your questions the best I can and see if I can help out. I'm sorry I don't have a full subscription so I cannot watch the full video to get the full context of why Jason is doing what he does but again I'll try to answer the best I can.

Why does he need to override the to_s method?

Jason is probably overriding the to_s method to help teach some points of programing, I can't watch the full video so I'm not sure of the why. But the to_s method is given to us for free from the Object class. So if we want to use the to_s method differently we need to override the class by defining to_s in our class and coding it how we want. In this case, maybe we want the full name, the last name, or last first name printed out. Otherwise if we did not define to_s in the Contact class, it would do the default code from the Object class which is, "The default to_s prints the object’s class and an encoding of the object id." I hope that helps.

why does he put ' ' around the variable names?

This one might be a little harder for me to explain, but I think it comes down to not being able to pass method names to a case statement and it call the method that you're attempting to pass in. What Jason is showing you is more of a simpler way to help show how to override and choose which method you'd like to print out with the to_s method. A more advance approach to this would be to override the to_s method and pass in the method name as a symbol, like so.

def to_s(format = :full_name)
    self.send(format)
end

^^ That allows you to send a method name as a symbol to the Contact class. So you could do something like:

name = Contact.new
name.first_name = 'Foo'
name.last_name = 'Bar'
name.to_s(:last_first)
>> "Bar, Foo"

Both ways accomplish the same thing.

Let me know if any of that helps. If not, let me know and I'll try to help some more.

Thanks, Neil