此代码中的调试类型错误

def print_and_sort(array)
    output_string = " "
    array.each do |element|
    output_string = output_string + " " + element
    end
    puts output_string
    array.sort
end


words = %w( all i can say is that my life is pretty plain )
words_with_nil = words.dup.insert(3, nil)
mixed_array = ["2", 1, "5", 4, "3"]

print_and_sort(words)
print_and_sort(words_with_nil)
print_and_sort(mixed_array)
def print_and_sort(array)
    output_string = "