On 11/15/19 11:26 AM, Dennis Lee Bieber wrote: > On Fri, 15 Nov 2019 12:56:02 +0100, "R.Wieser" <address@not.available> > declaimed the following: > >> There are quite a number of languages where /every/ type of argument >> (including values) can be transfered "by reference". Though some default to >> "by value", where others default to "by reference". >> > Yes -- and in those languages the concept of value vs reference is > visible at the source code level. In C, everything is passed by value -- > and the programmer uses & to pass (by value) the address of the argument, > and uses * in the called function to dereference that address back to the > data item itself. C++ added reference arguments (where the & is used in the > function declaration) in which the compiler automatically applies the > "address" and "dereference" operations.
There are languages where pass by reference is the default and not explicit. I remember in early FORTRAN being able to do something like this (its been years since I have done this so syntax is probably a bit off) PROCEDURE foo(i) i = 2 return then elsewhere you could do foo(j) and after that j is 2 you also could do foo(1) and after that if you did j = 1 then now j might have the value 2 as the constant 1 was changed to the value 2 (this can cause great confusion) later I believe they added the ability to specify by value and by reference, and you weren't allowed to pass constants by reference, -- Richard Damon -- https://mail.python.org/mailman/listinfo/python-list
