Thanks for all the replies.  I notice also that I can force changing of
the value (as opposed to the reference) by substituting a trivial
expression for the right-hand side of the assignment, e.g.

# g) Expression

myStringA = "Fred Shufflebotham"
myStringB = myStringA + ""
myStringB[0,4] = "Bert"

=> myStringA = "Fred Shufflebotham"
=> myStringB = "Bert Shufflebotham"

But of course it's an utter kludge.  Is there really no more elegant
way?

-- 
Posted via http://www.ruby-forum.com/.