name_that_error.rb

array = [[1],[2],[3]]

# 1 will it error? / name that error!
# 1a.
array.first + 1

# 1b.
array.first.first + 2

# 1c.
array.first.first.first + 3


# 2 will it error? / name that error!
array.first.map do |element|
  element * 4
end

# 3 will it error? / name that error!
array.each do |element|
  element.each do |sub_element|
    puts sub_element.first
  end
end

# 4 will it error? / name that error!
# 4a.
array.flatten.reverse.uniq.compact.reverse

# 4b.
array.flatten.uniq.compact.pop.reverse

# 5 will it error? / name that error!
array.each do |element|
  element + [element]
end