# lec 19 in class
# comments start with the hashtag (octothorp) symbol "#"

class Hello
  def my_first_method
    puts "Hello, World!"
  end
end

x = Hello.new
x.my_first_method




# generally don't use ";" at the end of a line in REPL (irb)







class A
  def m1
    34
  end

  def m2 (x, y)
    z = 7
    if x > y
      false
    else
      x + y * z
    end
  end
end

class B
  def m1
    4
  end

  def m3 x
    x.abs * 2 + self.m1
  end
end

class C
  def m1
    print "hi "
    self
  end
  def m2
     print "bye "
     self
  end
  def m2
    print "yo"
    self
  end
  def m3
    print "\n"
    self
  end
end

# newlines often are significant in Ruby syntax
# indentation never matters though

class D
  def m1
    @foo = 0
  end

  def m2 x
    @foo = @foo + x
    @bar = 0
  end

  def foo
    @foo
  end
end

class E
  def initialize(f=0) # Ruby has default arguments
    @foo = f
  end

  def m2 x
    @foo += x
    @bar = 0
  end

  def foo
    @foo
  end
end

class F
  # we now add in a class-variable, class-constant, and class-method

  Zachs_Age = 33

  def self.reset_bar
    @@bar = 0
  end

  def initialize(f=0)
    @foo = f
  end

  def m2 x
    @foo += x
    @@bar += 1
  end

  def foo
    @foo
  end

  def foo= x
    @foo = x
  end

  def bar
    @@bar
  end
end