yield.rb

# what is a block?

# [1,2,3].each { |number| p number } 

# what is yield?

# def hello 
#   name = "harrison"
#   yield(5)
#   puts name
# end 

# result = hello do |number|
#   p number
# end 

# p result

class Array 
  def my_each 
    index = 0
    while index < self.length
      # puts self[index]
      yield
      index += 1
    end 
    return self
  end 
end 

result = [1,2,3].my_each do 
  puts "hello"
end 
p result

# 1. finish off my_each so that uts functionality is the same as .each

# 2. make your own .map (call it my_map)

# 3. make your own .select (call it my_select)