Roles of Variables

[Bruno Medeiros]

Robert Fraser wrote:
> bearophile wrote:
>> Quoted from the article: "Roles of Variables and Learning to Program" 
>> by Jorma Sajaniemi
>> http://cs.joensuu.fi/~saja/var_roles/abstracts/didinf05.html
>>
>> Roles of variables in novice-level procedural programming:
>> *Fixed value: A variable initialized without any calculation and not 
>> changed thereafter *Stepper: A variable stepping through a systematic, 
>> predictable succession of values *Follower: A variable that gets its 
>> new value always from the old value of some other variable 
>> *Most-recent: A variable holding the latest value encountered in going 
>> through a holder succession of values, or simply the latest value 
>> obtained as input *Most-wanted: A variable holding the best or 
>> otherwise most appropriate value holder encountered so far *Gatherer: 
>> A variable accumulating the effect of individual values 
>> *Transformation: A variable that always gets its new value with the 
>> same calculation from values of other variables *One-way flag: A 
>> two-valued variable that cannot get its initial value once its value 
>> has been changed *Temporary: A variable holding some value for a very 
>> short time only *Organizer: An array used for rearranging its elements
>>
>> I like that list. Even if it's not complete it covers many important 
>> cases.
>>
>> The "Fixed value" case is so important that in Java the language gives 
>> you an attribute to specify it. So if certain languages have an 
>> attribute to specify the fist case, I ask myself if in a language it 
>> can be useful to have attributes to specify other of those cases. I 
>> think not...
>>
>> Bye,
>> bearophile
> 
> I'm sure that list is being used in some CS 101 class and the tests all 
> have "label the type of each variable". The day the test is returned 
> there will then be 100 unhappy students arguing that every variable can 
> fall into multiple categories.

Pretty much, yeah, and rightly so.

-- 
Bruno Medeiros - Software Developer, MSc. in CS/E graduate
http://www.prowiki.org/wiki4d/wiki.cgi?BrunoMedeiros#D