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From: D Yuniskis on 15 Mar 2010 12:51
Hi Vladimir,

Vladimir Vassilevsky wrote:
>
> Royston Vasey wrote:
>> I'm pushing along trying to learn some C using MCC18. Can someone
>> please tell me what the "&" before the variable "variable" does or
>> means in the code below?
>
> This symbol means "the one with a tail should go down from the tree".

ROTFL!
From: linnix on 15 Mar 2010 12:51
On Mar 14, 10:01 pm, D Yuniskis <not.going.to...(a)seen.com> wrote:
> Royston Vasey wrote:
> > I'm pushing along trying to learn some C using MCC18. Can someone please
> > tell me what the "&" before the variable "variable" does or means in the
> > code below? I'm finding it hard to find basic info like this in the
> > documentation I've found.
>
> > Is it AND? AND with what?
>
> >     ee_read_byte(0x00, &cal_var); //initialise calibration variable from
> > eeprom
>
> > why the "&" -----------^
>
> read as: "address of" ...
>

I always wonder why they did not use @. It would have been much
clearer. After all, it was designed by a committee of two only.

From: Royston Vasey on 15 Mar 2010 22:14

"Hans-Bernhard Br�ker" <HBBroeker(a)t-online.de> wrote in message
news:hnl8hm$i14$00$1(a)news.t-online.com...
> Royston Vasey wrote:
>
>> I'm pushing along trying to learn some C using MCC18. Can someone please
>> tell me what the "&" before the variable "variable" does or means in the
>> code below? I'm finding it hard to find basic info like this in the
>> documentation I've found.
>
> That's because you've either been looking for the wrong kind of
> documentation, or you've tackled this whole "learning a programming
> language" task entirely the wrong way round.
>
> What you actually need is introductory documentation of the C programming
> language, a.k.a. a C textbook. The 2nd edition of the one by Kernighan &
> Ritchie, who invented the language, is still among the best.
>
> And the right order of things is not to jump in and try to understand
> existing code by guessing what each letter in it means, but to actually
> _learn_ the language first, then apply that knowledge to existing code.

Thanks for the reply. I dont doubt you are correct with your comments re my
approach! :)


From: Royston Vasey on 15 Mar 2010 23:02

"D Yuniskis" <not.going.to.be(a)seen.com> wrote in message
news:hnkhol$rsc$1(a)speranza.aioe.org...
> Royston Vasey wrote:
>> I'm pushing along trying to learn some C using MCC18. Can someone please
>> tell me what the "&" before the variable "variable" does or means in the
>> code below? I'm finding it hard to find basic info like this in the
>> documentation I've found.
>>
>> Is it AND? AND with what?
>>
>> ee_read_byte(0x00, &cal_var); //initialise calibration variable from
>> eeprom
>>
>> why the "&" -----------^
>
> read as: "address of" ...
>
>> unsigned char ee_read_byte(unsigned char address, unsigned char *_data){
>
> ... because this expects a pointer (i.e., an address) ------------^^^^
>
>> EEADR = address;
>> EECON1bits.CFGS = 0;
>> EECON1bits.EEPGD = 0;
>> EECON1bits.RD = 1;
>> *_data = EEDATA;
>> }

thanks for that.


From: Nial Stewart on 16 Mar 2010 09:59
>> What you actually need is introductory documentation of the C programming language, a.k.a. a C
>> textbook. The 2nd edition of the one by Kernighan & Ritchie, who invented the language, is still
>> among the best.
>
> Thanks for the reply. I dont doubt you are correct with your comments re my approach! :)


As a hardware engineer who 'did some C at university' I found 'Practical C
Programming' (O'Reilly) very good.



Nial.


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