Given a String instance,  how to create a different but equivalent one

The code below shows the incorrect way and two correct ways
to create a second string instance that equal to a given string
instance.

Q1: Are there better ways to do this than the two I concocted?
Q2: How can I create a proc to invoke it with each of my candidate
assignment statements

I am interest in this issue because I made the naive assignment in a
project I am working on and
had to waste time trying debugging it.

Thanks in advance,
Richard


# Version 1: Wrong!

os = "abc"		# Original String
ws = os 		# Thinking ws can be modified independently of os.
3.times { ws << (ws[-1] + 1).chr; puts ws }
while ws.size > os.size
  ws.chop; puts ws
end

# Version 2: OK

puts
os = "abc"				# Original String
ws = String.new(os) 		# ws is a reference to a different string
oobject than os but initially equal to os
3.times { ws << (ws[-1] + 1).chr; puts ws }
while ws.size > os.size
  ws.chop!; puts ws
end

# Version 3: OK

puts
os = "abc"				# Original String
ws = os + "" 			# A less verbose way to get a new string object
initially equal to os
3.times { ws << (ws[-1] + 1).chr; puts ws }
while ws.size > os.size
  ws.chop!; puts ws
end