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Re: null array [message #36471]

Wed, 24 September 2003 18:35

David Fanning
Messages: 11724
Registered: August 2001

Senior Member

Tomson writes:

> But What I want to do is to initialize several arrays which are in common
> block and their length will be changed for different call and the lengths
> of them may be zero. If the lengthes of them are zero, the process will be
> changed. If there isnot any initialization, the array return to the main
> program may be the former ones.

If I understand you correctly, you may find a pointer
useful in this situation. A pointer could point to
a "null array", in the sense that it would point to
an "undefined variable":

ptr = Ptr_New(/Allocate_Heap)
IF N_Elements(*ptr) EQ 0 THEN Print, 'Pointer undefined' ELSE $
*ptr = [initValue]

Cheers,

David

--
David W. Fanning, Ph.D.
Fanning Software Consulting, Inc.
Phone: 970-221-0438, E-mail: david@dfanning.com
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[Message index]

		Re: null array By: David Fanning on Wed, 24 September 2003 18:35
		Re: null array By: tomson on Wed, 24 September 2003 17:47
		Re: null array By: JD Smith on Wed, 24 September 2003 09:17
		Re: null array By: R.Bauer on Wed, 24 September 2003 08:11
		Re: null array By: Paul Van Delst[1] on Wed, 24 September 2003 06:52
		Re: null array By: Ben Panter on Wed, 24 September 2003 02:08
		Re: null array By: Ben Panter on Wed, 24 September 2003 01:33
		Re: null array By: R.Bauer on Tue, 23 September 2003 20:21
		Re: null array By: David Fanning on Tue, 23 September 2003 20:04
		Re: null array By: David Fanning on Fri, 26 September 2003 02:24
		Re: null array By: Stein Vidar Hagfors H[2] on Tue, 30 September 2003 12:36

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