Using ruby blocks to write a map function

ruby-block-example.rb

# built-in map

squares = [1,2,3].map do |n|
    n * n
end

puts squares

# if you wanted to write your own

def my_map_method(array)
    return array.clone unless block_given?
    results = []
    for item in array
        results.push(yield item)
    end
    results
end

more_squares = my_map_method([1,2,3]) do |n|
    n * n
end

puts more_squares

# equivalent syntax for blocks, just because:
even_more_squares = my_map_method([1,2,3]) { |n| n * n }

puts even_more_squares