Ruby Classes and Objects - Inheritance
(Page 4 of 4 )
Yes, it's what we're all waiting for: that big fat pay check from our dear old dead uncle whom we hardly knew. I mean, it was great catching the baseball with him and all, but now that he left his gigantic fortune, you can buy your own baseball team and have them throw you the ball. Or better yet, you can buy a whole squad of cheerleaders and have them...well cheer.
While not nearly as exciting as our above example, Ruby (like other programming languages) allows you to pass the things one class has down to another.
Let's say we start a new class, called oh I don't know...computer programmers. Maybe we'll call it Nerds for short. What are some things you might notice about a nerd? They might wear funny glasses and pocket protectors. When they go to the salon they might have the hair stylist place a bowl on their head and trim around it. Maybe they wear those brown corduroys pulled up to their neck so that they look like a turtle. These are all things we can say a nerd (or at least the cliche of a nerd) possesses.
But maybe the nerd class is too broad. What if we want a small group of people. How about Ruby Nerds? Now although Ruby Nerds is a new class, let's face it...in the grand scheme of things they are still Nerds, and thus possess the same things. This my friends, is inheritance.
Basically inheritance it saves the programmer time and coding; he no longer needs to describe the new class, since it is a subclass of a class and possesses the same traits since it is from the same background.
Here's how that looks in code:
class Nerd # Superclass
def initialize(action)
@action = action
end
def retrieve_action
return @action
end
end
class Ruby_Nerd < Nerd # informs program Ruby_Nerd is a child of Nerd
def initialize (action, reaction)
super(action) #says to get the action from the superclass
@reaction = reaction
end
def retrieve_reaction
return @reaction
end
end
ruby_nerd = Ruby_Nerd.new("trip", "red")
puts "You " + ruby_nerd.retrieve_action + "in front of a girl!"
puts "Your face turns " + ruby_nerd.retrieve_reaction + ruby_nerd.retrieve_reaction + ruby_nerd.retrieve_reaction
The previous code would produce the following output:
You trip in front of a girl!
Your face turns red red red
Well, we covered a lot of ground in this tutorial, but surprisingly enough, there is still more you need to know about Objects and Classes. We'll have to get to that in the next tutorial however, because I am out of space here. So join us next time, when we'll learn more about the awesome things you can do with Ruby.
| DISCLAIMER: The content provided in this article is not warranted or guaranteed by Developer Shed, Inc. The content provided is intended for entertainment and/or educational purposes in order to introduce to the reader key ideas, concepts, and/or product reviews. As such it is incumbent upon the reader to employ real-world tactics for security and implementation of best practices. We are not liable for any negative consequences that may result from implementing any information covered in our articles or tutorials. If this is a hardware review, it is not recommended to open and/or modify your hardware. |
