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void before main ()

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seo2005

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void before main ()

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Oct 19th, 2009

I am a beginner in c and would like someone tp help me . My question is why I have to write void before main to execute the c program.

#include<stdio.h>

void main()

clrscr();

{
printf("Hello")

}

This is a very simple program. But I am unable to execute it if I don't write void before main().

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gerard4143 gerard4143 is offline

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Oct 19th, 2009

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Originally Posted by seo2005

I am a beginner in c and would like someone tp help me . My question is why I have to write void before main to execute the c program.

#include<stdio.h>

void main()

clrscr();

{
printf("Hello")

}

This is a very simple program. But I am unable to execute it if I don't write void before main().

That must be an old text...It should be

 Help with Code Tags 
 C Syntax (Toggle Plain Text) 
int main()
{
printf("Hello");
return 0;
}
int main()
{
printf("Hello");
return 0;
}

Last edited by gerard4143; Oct 19th, 2009 at 1:09 am.

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MrNoob

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Oct 19th, 2009

also remeber don't use void main since u might want to check it's return value if it's return sucess or right also main is a specailized function which alawys start the program at like entry point for example . u should see some tutorials on c before doing anything on it.

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seo2005

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Oct 19th, 2009

Is it true that some compilers require void before main ?
Also when I declare a variable like this

int a,b,c;

the error shown is : The declaration is not allowed.

Why this error ?

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SecurExpert SecurExpert is offline

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Oct 19th, 2009

Use void to tell the compiler that the function is not expected to return a value. Use int if the function returns a value. By the way its also dependent on the compiler. Some may demand the void like in your case, so use it, that is if the program returns a value.

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Tom Gunn

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Oct 19th, 2009

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Is it true that some compilers require void before main ?

No. Any compiler that claims to compile C is required to allow a return value of int from main(). A return of void from main() is an extension that only some compilers allow. These two definitions of main(), and anything equivalent, are the only correct and portable options:

 Help with Code Tags 
 C Syntax (Toggle Plain Text) 
int main()
{
    /*...*/
}
int main()
{
    /*...*/
}

 Help with Code Tags 
 C Syntax (Toggle Plain Text) 
int main(int argc, char* argv[])
{
    /*...*/
}
int main(int argc, char* argv[])
{
    /*...*/
}

•

Why this error ?

I cannot say without seeing more code. It is probably in the wrong place, judging from the misplacement of clrscr() in your first post.

-Tommy (For Great Justice!) Gunn

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Harsh B.C.A. Harsh B.C.A. is offline

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Oct 19th, 2009

[QUOTE=seo2005;1019063]I am a beginner in c and would like someone tp help me . My question is why I have to write void before main to execute the c program.

#include<stdio.h>

void main()

clrscr();

{
printf("Hello")

}

of course it is a simple program but the void is responsible to return the value.if u dont put void before main() then how should ur program return the desire value.......

but you can also run the program without puting void......
try it.........

#include<stdio.h>
main()
{
clrscr();
printf("hello");
return 0()
}

here return 0() work as void and it returns the vlue of program..

note:-
1) put ; after the end of printf("hello");
===============================================

i hope my answer satisfies you.......