Can someone help write a standalone method that produces this output?

gistfile1.txt

s = %W/This
is
a
test./
print "Number of lines: ", count_lines(s), "\n"
# Output:
Number of lines: 4

def count_lines string
  string.lines.size
end

count_lines "hi\nthere"
#=> 2

def print_line_count string
  puts "Number of lines: #{count_lines string}"
end

print_line_count "hi\nthere"
# Number of lines: 2
#=> nil