why error C2051?

[clino]

const int c=9;

void main()
{
int a=9;
switch (a)
{
case c:
a=c+1;
break;
}
}
-----------
compile result:
c.c(8) : error C2051: case expression not constant
-----------
But [c] is a const int....why?

[Richard Heathfield]

clino said:

const int c=9;

void main()

int main(void)

{
int a=9;
switch (a)
{
case c:
a=c+1;
break;
}
}
-----------
compile result:
c.c(8) : error C2051: case expression not constant
-----------
But [c] is a const int....why?

It's a const int all right, but it isn't a constant integer expression,
which is what you need in a case expression.

--
Richard Heathfield
"Usenet is a strange place" - dmr 29/7/1999
http://www.cpax.org.uk
email: normal service will be restored as soon as possible. Please do not
adjust your email clients.

[Richard Bos]

"clino" <zh**********@g mail.comwrote:

const int c=9;

void main()

<http://c-faq.com/ansi/maindecl.html>
<http://c-faq.com/ansi/voidmain.html>
<http://c-faq.com/ansi/voidmain3.html>
<http://c-faq.com/ansi/voidmainbooks.h tml>

{
int a=9;
switch (a)
{
case c:
a=c+1;
break;
}
}
-----------
compile result:
c.c(8) : error C2051: case expression not constant
-----------
But [c] is a const int....why?

<http://c-faq.com/cpp/constvsdefine.h tml>
<http://c-faq.com/ansi/constasconst.ht ml>

HTH; HAND; RTFFAQ.

Richard

[clino]

very clearly~
Thank u very much~

On 11ÔÂ17ÈÕ, ÏÂÎç4ʱ08·Ö, [e-mail] (Richard
Bos) wrote:

"clino" <zhangchun...@g mail.comwrote:

const int c=9;

void main()<http://c-faq.com/ansi/maindecl.html>

<http://c-faq.com/ansi/voidmain.html>
<http://c-faq.com/ansi/voidmain3.html>
<http://c-faq.com/ansi/voidmainbooks.h tml>

{
int a=9;
switch (a)
{
case c:
a=c+1;
break;
}
}
-----------
compile result:
c.c(8) : error C2051: case expression not constant
-----------
But [c] is a const int....why?<htt p://c-faq.com/cpp/constvsdefine.h tml>

<http://c-faq.com/ansi/constasconst.ht ml>

HTH; HAND; RTFFAQ.

Richard