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Started by Ron Kerr
Tue, 25 Jun 1996 00:00
Re: value change
Author: Ron Kerr
Date: Tue, 25 Jun 1996 00:00
Date: Tue, 25 Jun 1996 00:00
37 lines
2211 bytes
2211 bytes
Frans Panken writes: > > Can anyone give me any comments on the following: > > Suppose a procedure activates a PROCESS CLASS with a local ARRAY "A" > as parameter. When after activation of this process class the array > "A" is changed within the procedure, the local array in the class > that was just activated changes as well ! > This does not occur in the case of reals, integers, booleans etc. > > So, if a procedure activates a number (say N) of classes and passes > arrays to these classes, the values in the local arrays of classes 1 > .. N-1 change into the values given to the class which was activated > last (i.e. class number N). > > This observation worries me a bit; are there any other declarations > that will change in this manner ?? If I understand your question correctly, the changes to the arrays occur only if they are transmitted to the classes "by reference", the default transmission mode for arrays. (Transmission by reference merely passes a pointer and so does not give a copy local to the class object.) If you specify the array parameters in the class headings as "value", the class objects will have local copies in the same manner as reals, integers, etc. The "value" transmission mode is not available for reference arrays. Hope that helps. Cheers....Ron ------------------------------------------------------------------------ Ron Kerr, Computing Service, Newcastle University, NE1 7RU, England. Tel. +44 191 222 8187 Fax. +44 191 222 8765 (NOTE new area code) ------------------------------------------------------------------------
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