this_message_will_self_destruct.rb

def destroy_message!(string)
  #TODO: remove the message from string destructively!
  new_string=string[/[\W|\w]*:/]    # '*:' is the whole thing b4 the * + inclusive of *
  if string.include? ':'
  	string.sub!(string,new_string)
  else 
  	string
  end
end

def destroy_message!(string)
  #TODO: remove the message from string destructively!
  new_string=string[/[\W|\w]*:/]
  if string.include? ':'
  	string.!sub(string,new_string)  # permanently modify the value
  else 
  	string
end

# Driver code... 
string = "this message will self-destruct: you can't hug every cat"
original_string = string.dup
puts destroy_message(string) == "this message will self-destruct:"
puts string == original_string # we shouldn't modify the string passed to destroy_message

string = "this has no message"
original_string = string.dup
puts destroy_message(string) == string
puts string == original_string # we shouldn't modify the string passed to destroy_message

string = "this message will self-destruct: you can't hug every cat"
original_string = string.dup
destroy_message!(string)
puts string == "this message will self-destruct:"
puts string != original_string

string = "this has no message"
result = destroy_message!(string)
puts result.nil?
puts string == string