-> Yes, that's what I was trying to explain to Richard. People who learned
-> the ANSI / ISO Standard way of doing it (by Reference) actually use
-> and rely on that default. People who learned on BBC and some other
-> variants where the default is by value won't use calling by Reference
-> as often. Of course these are just tendencies, not hard and fast
rules.
-> I'm sure there are some Standard users who don't use the changed
-> parameters just as there are some BBC users who do.
-> Tom Lake
If the language is set up to call by reference, it's easy to write code
that effectively calls by value, e.g.:
CALL Twiddle (X + 0)
If Twiddle changes the value of its input parameter, the value of X in
the calling routine will *not* be changed.
But how easy is it to do the other way around? If the language is set
up to call by value, can we write simple code that effectively calls by
reference? I can't think of an easy way to do it.
Of course, the language may have specific commands to switch from one
method of calling to the other, but without them, a dialect that calls
by value can't easily be made to call by reference.
dow
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