byVal - was it ever the default? | keyongtech

byVal - was it ever the default? | keyongtech — Thu, 22 Jan 2009 06:27:44 GMT

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re: More On ByRef vs ByVal

David Reed — Wed, 05 Jul 2006 14:47:39 GMT

Just thought I'd say for anyone else googling to this that in VBScript "By Reference" does not mean two different things. It _always_ means a pointer to the data rather than the data itself. I think what FAIC was getting at is that for intrinsic types (integer, float, string, etc) the variable contains the actual value (e.g. variable intX actually contains the number 3) whereas for object types the variable contains a pointer to the actual object (e.g. variable objX contains a memory location value a.k.a. a pointer to the object). Thus when dealing with objects, everything you do is implicilty "By Reference", wherea when dealing with intrinsic types, everything you do is implicitly by "By Value". Incidentally this does not affect the rules behind passing variables ByRef and ByVal i.e. passing an object variable ByRef allows you to change the variable value, in this case a the pointer to the object data, which means you can reassign it to another object whereas passing ByVal does not (however, and this is where people get confused, irrespective of passing an object variable ByRef or ByVal you can always change the underlying object data), and passing an intrinsic variable ByRef allows you to change the variable value, in this case the actual data, whereas passing ByVal does not. C programmers tend to understand all this implicilty because of their knowledge of pointers and how languages work under the hood, but VB programmers tend to have difficuly grasping what is going on because of thier lack of exposure to pointers.

re: Are JScript strings passed by reference?

Fabulous Adventures In Coding — Tue, 01 Jun 2004 08:48:00 GMT

re: Aaargh, Part Six: One More Thing About Comments

Fabulous Adventures In Coding — Thu, 06 May 2004 20:05:00 GMT

re: Aaargh, Part Six: One More Thing About Comments

Fabulous Adventures In Coding — Thu, 06 May 2004 19:50:00 GMT

re: Aaargh, Part Six: One More Thing About Comments

Fabulous Adventures In Coding — Thu, 06 May 2004 19:44:00 GMT

In, Out, In-Out, Make Up Your Mind Already

Fabulous Adventures In Coding — Thu, 19 Feb 2004 04:54:00 GMT

I was talking about reference types vs. by-reference variables a while back. Recall that both JScript and VBScript have reference types (ie, objects) but JScript does not have by-reference variables. COM supports passing variable references around, but unfortunately the intersection of early-bound COM and late-bound IDispatch is a little bit goofy.