Object Oriented Programming Part 1 (Classes)

Question 1

Create a basic class

Answer 1

class Person

end

Question 2

What are the different kind of variables when it comes to classes in Ruby and explain what each one means?

Answer 2

global variables: available everywhere
local variables: available only within certain methods
class variables: available to a certain a class
instance variables: available to certain instances of a class

Question 3

What is the correct syntax for each kind of variable?

Answer 3

Global: $age
Instance: @age
Class: @@age
Local: age

Question 4

Fix the following class so that my_variable can be printed out to the console, write out both ways please

class MyClass
  my_variable = "Hello!"
end

puts my_variable

Answer 4

class MyClass
  $my_variable = "Hello!"
end

puts $my_variable

or

my_variable = "Hello!"
class MyClass

end

puts my_variable

Question 5

How would you create a class that inheritance from the class Animal?

class Animal
def initialize(name, age)
@name = name
@age = age
end

Answer 5

class Animal
def initialize(name, age)
@name = name
@age = age
end
end

class Fish < Animal

end

Question 6

Create a class called Dragon that overrides the fight method in the Creature class.

class Creature
  def initialize(name)
    @name = name
  end

def fight
return “Punch to the chops!”
end
end

Answer 6

class Creature
  def initialize(name)
    @name = name
  end

def fight
return “Punch to the chops!”
end
end

class Dragon
def fight
return "Breathes fire!"
end

Question 7

If you want to write a class or method with nothing inside of it, whats a very quick/short way of writing this?

Answer 7

class Monkey; end