freelanceprogrammers.org Forum Index » C
What`s the order of evaluation of preprocessor?
Joined: 05 Jan 2005
Posts: 2
What`s the order of evaluation of preprocessor?
#define f(a,b) a##b
#define g(a) #a
#define h(a) g(a)
int main()
{
printf("%s
",h(f(1,2)));
printf("%s
",g(f(1,2)));
return 0;
}
Output of this program will be :
12
f(1,2)
I am unable to understand the output.
Plz explain it.
Thanks in advance
Naveen
Joined: 25 Jul 2003
Posts: 48
What`s the order of evaluation of preprocessor?
Reply embeddd...
> From: Naveen Khattar [mailto:nkhattar@...]
> Sent: Wednesday, January 05, 2005 5:37 AM
> To: programmers-town@yahoogroups.com
> Cc: Naveen Khattar
> Subject: (PT) What`s the order of evaluation of preprocessor?
>
> #define f(a,b) a##b
> #define g(a) #a
> #define h(a) g(a)
>
> int main()
> {
> printf("%s
",h(f(1,2)));
> printf("%s
",g(f(1,2)));
> return 0;
> }
>
> Output of this program will be :
> 12
> f(1,2)
>
> I am unable to understand the output.
Do you know how preprocessor directives work?
> Plz explain it.
Already answered in the archive:
< http://groups.yahoo.com/group/Programmers-Town/message/3060 >
HTH
Shyan
Joined: 05 Jan 2005
Posts: 2
What`s the order of evaluation of preprocessor?
-----Original Message-----
From: Shyan Lam [mailto:sflam@...]
Sent: Thursday, January 06, 2005 1:22 AM
To: Programmers-Town@yahoogroups.com
Subject: RE: (PT) What`s the order of evaluation of preprocessor?
Reply embeddd...
> From: Naveen Khattar [mailto:nkhattar@...]
> Sent: Wednesday, January 05, 2005 5:37 AM
> To: programmers-town@yahoogroups.com
> Cc: Naveen Khattar
> Subject: (PT) What`s the order of evaluation of preprocessor?
>
> #define f(a,b) a##b
> #define g(a) #a
> #define h(a) g(a)
>
> int main()
> {
> printf("%s
",h(f(1,2)));
> printf("%s
",g(f(1,2)));
> return 0;
> }
>
> Output of this program will be :
> 12
> f(1,2)
>
> I am unable to understand the output.
Do you know how preprocessor directives work?
That`s what I want to know.
> Plz explain it.
Already answered in the archive:
< http://groups.yahoo.com/group/Programmers-Town/message/3060 >
HTH
Shyan
To unsubscribe : programmers-town-unsubscribe@yahoogroups.com
Yahoo! Groups Links
Joined: 06 Jan 2005
Posts: 2
What`s the order of evaluation of preprocessor?
Hi,
#define f(a,b) a##b
#define g(a) #a
#define h(a)
Here ,# represent string tokenizers.It just concatenate the two strings.Thatis
where ever f(a,b) is used it will be replaced by ab.So,as per urprogram it will be replaces as 12.
I think u understand.
Thank U
Karthikeyan.R
Quoting nkhattar@...:
>
-----OriginalMessage-----
From: Shyan Lam [mailto:sflam@...]
Sent: Thursday, January 06, 2005 1:22 AM
To:Programmers-Town@yahoogroups.com
Subject: RE: (PT) What`s the orderof evaluation of preprocessor?
Replyembeddd...
> From: Naveen Khattar[mailto:nkhattar@...]
> Sent: Wednesday, January 05, 20055:37 AM
> To: programmers-town@yahoogroups.com
> Cc:Naveen Khattar
> Subject: (PT) What`s the order of evaluation ofpreprocessor?
>
> #define f(a,b) a##b
> #defineg(a) #a
> #define h(a) g(a)
>
> intmain()
> {
> printf("%sn",h(f(1,2)));
> printf("%sn",g(f(1,2)));
> return0;
> }
>
> Output of this program will be:
> 12
> f(1,2)
>
> I am unable tounderstand the output.
Do you know how preprocessordirectives work?
That`s what I want to know.
>Plz explain it.
Already answered in the archive:
href="http://groups.yahoo.com/group/Programmers-Town/message/3060">http://groups.yahoo.com/group/Programmers-Town/message/3060>
HTH
Shyan
Tounsubscribe : programmers-town-unsubscribe@yahoogroups.com
Yahoo! Groups Links
To unsubscribe :programmers-town-unsubscribe@yahoogroups.com
align=center>Yahoo! GroupsSponsor
align=center>ADVERTISEMENThref="http://us.ard.yahoo.com/SIG=129bj7pn1/M=298184.5639630.6699735.3001176/D=groups/S=1705006788:HM/EXP=1105079504/A=2495202/R=0/SIG=11evjk50a/*http://www.netflix.com/Default?mqso=60188913" alt="">src="http://us.a1.yimg.com/us.yimg.com/a/ne/netflix/121504_y1204_a_300250a.gif" alt="click here" width="300" height="250"border="0">
width=1 height=1src="http://us.adserver.yahoo.com/l?M=298184.5639630.6699735.3001176/D=groups/S=:HM/A=2495202/rand=893197294">
Yahoo! Groups Links
To visit your group on the web, go to:href="http://groups.yahoo.com/group/Programmers-Town/">http://groups.yahoo.com/group/Programmers-Town/
To unsubscribe from this group, send an email to:href="mailto:Programmers-Town-unsubscribe@yahoogroups.com?subject=Unsubscribe">Programmers-Town-unsubscribe@yahoogroups.com
Your use of Yahoo! Groups is subject to the href="http://docs.yahoo.com/info/terms/">Yahoo! Terms ofService.
Joined: 25 Jul 2003
Posts: 48
What`s the order of evaluation of preprocessor?
Reply at end...
> -----Original Message-----
> From: Naveen Khattar [mailto:nkhattar@...]
> Sent: Thursday, January 06, 2005 12:28 AM
> To: Programmers-Town@yahoogroups.com
> Subject: RE: (PT) What`s the order of evaluation of preprocessor?
>
>
> > Do you know how preprocessor directives work?
> That`s what I want to know.
How about some reading first:
<http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vclang/htm
l/_predir_preprocessor_operators.asp>
(URL might line-break by mail client)
Consult your compiler`s documentation and see how to generate a
"preprocessed" output to see the result just after preprocessing.
HTH
Shyan
All times are GMT
Page 1 of 1
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
Freelace Website Designer - Customer web design and software building.
China Wholesale - Electronics Products
Character Studio - Tutorials and Help
China Wholesale - Electronics Products
Character Studio - Tutorials and Help