It's late and I don't have a lot of creativity in me tonight. So I'm going to write this blog post, and you're going to help me get through it. With wine.
To start, I'll tell you a few things that happen to me when I drink wine:
1. I'll have another glass. If I've had more than 4, I'll fall asleep.
2. I'll start drawing much creepier things.
3. Once I hit 4 glasses, I'll fall asleep. Until then, I'll party it up!
To make this worthy of a blog post, I suppose we'll have to throw some code in here. We're going to make a new object Class in Ruby to define all the things that happen to me when I'm drunk. We'll call it the Drunk class:
class Drunk
def initialize(name)
@person = name
end
end
What this code does is create a new class called Drunk, that is initialized with a name argument. Whenever you create a new class, you have to initialize it with something. Anything that will be called on throughout your class should be initialized in the initialize method. Now, when I type this into irb:
i = Drunk.new("aarthi")
I'll get a new Ruby object! Because the argument "name" that I passed into the initialize method was "aarthi", my new i object will have an instance variable @person = "aarthi". (Keep in mind, I called my new object "i" because my story is about me. Ruby objects can be named whatever you want: feel free to call your new Drunk person "my_roommmate" with name "jimmy_jay".)
Now that I'm our new Drunk person, we have to define some of my drunken characteristics. First, I have to figure out if I'm allowed to have another drink. We don't know how many I've had yet, so let's figure out a way to get that.
Instead of passing a new argument into my i object, I could just initialize the class with another variable. Since we want this program to be dynamic (I'm sure I'll find a reason to drink wine again tomorrow), let's have the program ask me how much I've had already.
class Drunk
def initialize(name)
@person = name
puts "How many drinks have you had?"
@number_of_drinks = gets.chomp.to_i
end
end
Here, I'm creating a new instance variable called @number_of_drinks that will ask me for a number, and change the String response to an Integer response. Because I defined this instance variable in the intialize method, and called on an instance by creating a new object in the class, I now have a @number_of_drinks variable that is accessible throughout my class, and is equal to a number I enter into the program after creating object i.
Great. So now we know how many drinks I've had. If it's any more than 4, we know I'm toast. If I want to have another, I'll have to check on that.
class Drunk
def initialize(name)
@person = name
puts "How many drinks have you had?"
@number_of_drinks = gets.chomp.to_i
end
end
def have_another
if @number_of_drinks < 4
@number_of_drinks += 1
puts "You've had #{@number_of_drinks} drinks."
else
puts "Go to bed."
end
end
end
Now, if I run my new method have_another on my object i:
i.have_another .
First, my program will check the instance variable @number_of_drinks. Let's say tonight I've had 2. Because @number_of_drinks is less than 4, I will now have one more! @number_of_drinks is now equal to 3.
So what will happen if I run i.have_another two more times? The first time, I'll be allowed one more drink. The second time, @number_of_drinks will no longer be less than 4, and I'll be told to go to bed (boooooo).
Now, usually I don't really have anyone telling me to go to bed. It just sort of happens in a wine induced haze. Let's see how we'd code that:
class Drunk
def initialize(name)
@person = name
puts "How many drinks have you had?"
@number_of_drinks = gets.chomp.to_i
end
def have_another
if @number_of_drinks < 4
@number_of_drinks += 1
puts "You've had #{@number_of_drinks} drinks."
else
go_to_bed
end
end
def go_to_bed
puts "#{@person} is asleep."
end
end
Now, if I have over 4 drinks, the have_another method will automatically call on the go_to_bed method. The go_to_bed method just says that the @person is asleep.
If I didn't want to have_another, but instead wanted to go_to_bed, I could directly call that method using i.go_to_bed . Then, regardless of whether or not I hit my 4 drink max, I'd be asleep.
Now, I have to account for my strange drawings. Let's create a new method for that. It'll get called on automatically when i.have_another, as long as I didn't go_to_bed yet.
class Drunk
def initialize(name)
@person = name
puts "How many drinks have you had?"
@number_of_drinks = gets.chomp.to_i
end
def have_another
if @number_of_drinks < 4
@number_of_drinks += 1
puts "You've had #{@number_of_drinks} drinks."
draw_a_thing
else
go_to_bed
end
end
def go_to_bed
puts "#{@person} is asleep."
end
def draw_a_thing
art_ideas = ["a unicorn in an airport", "a melty whale", "an alien singing opera"]
drawing = art_ideas.sample
puts "You've drawn #{drawing}"
end
end
In my instance method draw_a_thing, I created an art_ideas array with all my drunken ideas for what to draw. My drawing will be a random sample from my art_ideas array. Here, you can see that I didn't actually use an instance variable. That's because the only method that calls on my drawing variable is my draw_a_thing method.
So now let's get real wild and crazy. Let's assume that, every time I drink some wine, I'll keep going till I hit 4 glasses. For that, I'll need to call on my instance methods right in my initialize step! I'll also have to turn my have_another method into a while loop, so i.have_another until i.go_to_bed.
class Drunk
def initialize(name)
@person = name
puts "How many drinks have you had?"
@number_of_drinks = gets.chomp.to_i
have_another
end
def have_another
while @number_of_drinks < 4
@number_of_drinks += 1
puts "You've had #{@number_of_drinks} drinks."
draw_a_thing
end
go_to_bed
end
def go_to_bed
puts "#{@person} is asleep."
end
def draw_a_thing
art_ideas = ["a unicorn in an airport", "a melty whale", "an alien singing opera"]
drawing = art_ideas.sample
puts "You've drawn #{drawing}"
end
end
Pretty cool, right? All we had to do to run this entire program was create a new object in the Drunk class. After typing this into irb:
i = Drunk.new("aarthi")
This all happened:
How many drinks have you had?
1 #This was my response
You've had 2 drinks.
You've drawn an alien singing opera
You've had 3 drinks.
You've drawn a melty whale
You've had 4 drinks.
You've drawn a unicorn in an airport
aarthi is asleep.
So now it looks like I owe you a drunken drawing. I'll go with what the program told me: I hope you enjoy the unicorn in an airport.