slice.rb

# Given an array of arrays:
# ?
# 1
# array = [[2,3,4], [5,6,7], [6,7,8]]
#
# Write a piece of code that will take that array and
#give back an array of arrays with each element multiplied by itself so you will get back:
# ?
# 1
# [[4, 9, 16], [25, 36, 49], [36, 49, 64]]

a1 = [[2,3,4], [5,6,7], [6,7,8]]
a2 = []

a1.each do |x|
sub_array = []
  if( x.is_a? Array)
    x.each do |y|
      sub_array << y * y
    end
  else
    puts "error"
  end
a2 << sub_array
end

puts "your original string is: "
print a1
puts
puts "after conversion it is now: "
print a2
puts

a = [[1,2,3],[4,5,6],[7,8,9]]
a = a.flatten
b = a.map {|x| x = x*x}.each_slice(3).to_a
print b
puts