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Rahul
Guest
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 Posted: Wed Jul 12, 2006 9:10 am Post subject: Defining a variable in switch statement |
 |
|
Hi,
Is the following correct? Here i have declaread a char array in case 1:
and am using the same in case 2:
first I tried another definition of ch in case 2: assuming that if i=2
then char ch[] will not get allocated in case 1:. But the compiler gave
me (re-definition error) so i removed it and now its working fine.
Is it correct as per the standard?
switch (i)
{
case 1:
char ch[12];
strcpy(ch, "case 1\n");
cout<<ch;
break;
case 2:
strcpy(ch, "case 2\n"); //Can i use it here, when i=2, why
should the compiler allocate
// the variable shich is
declared in the case which is not true.
cout<<ch;
break;
default:
strcpy(ch, "default\n"); // Is it ok here also?
cout<<ch;
} |
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Forest
Guest
|
| Posted: Wed Jul 12, 2006 9:10 am Post subject: Re: Defining a variable in switch statement |
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|
You can use { and } to meet your requirement.
[example]
switch ( i )
{
case 1:
{
char ch[1];
//...
break;
}
case 2:
{
char ch[2];
//...
break;
}
//...
}
[end example]
Rahul wrote:
| Quote: | Hi,
Is the following correct? Here i have declaread a char array in case 1:
and am using the same in case 2:
first I tried another definition of ch in case 2: assuming that if i=2
then char ch[] will not get allocated in case 1:. But the compiler gave
me (re-definition error) so i removed it and now its working fine.
Is it correct as per the standard?
switch (i)
{
case 1:
char ch[12];
strcpy(ch, "case 1\n");
cout<<ch;
break;
case 2:
strcpy(ch, "case 2\n"); //Can i use it here, when i=2, why
should the compiler allocate
// the variable shich is
declared in the case which is not true.
cout<<ch;
break;
default:
strcpy(ch, "default\n"); // Is it ok here also?
cout<<ch;
} |
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Jakob Bieling
Guest
|
| Posted: Wed Jul 12, 2006 9:10 am Post subject: Re: Defining a variable in switch statement |
|
|
Forest <LuckyYong (AT) gmail (DOT) com> wrote:
| Quote: | You can use { and } to meet your requirement.
|
Please do not top-post. Always place it below the relevant part of
the message you are replying to. It just makes live easier for most of
us, as we are used to reading articles/books from top to bottom and not
from bottom to top.
regards
--
jb
(reply address in rot13, unscramble first) |
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Rahul
Guest
|
| Posted: Wed Jul 12, 2006 9:10 am Post subject: Re: Defining a variable in switch statement |
|
|
Forest wrote:
| Quote: | You can use { and } to meet your requirement.
[example]
switch ( i )
{
case 1:
{
char ch[1];
//...
break;
}
case 2:
{
char ch[2];
//...
break;
}
//...
}
[end example]
Rahul wrote:
Hi,
Is the following correct? Here i have declaread a char array in case 1:
and am using the same in case 2:
first I tried another definition of ch in case 2: assuming that if i=2
then char ch[] will not get allocated in case 1:. But the compiler gave
me (re-definition error) so i removed it and now its working fine.
Is it correct as per the standard?
switch (i)
{
case 1:
char ch[12];
strcpy(ch, "case 1\n");
cout<<ch;
break;
case 2:
strcpy(ch, "case 2\n"); //Can i use it here, when i=2, why
should the compiler allocate
// the variable shich is
declared in the case which is not true.
cout<<ch;
break;
default:
strcpy(ch, "default\n"); // Is it ok here also?
cout<<ch;
}
|
That I have done, But I wanted to know is the above behaviour as per
the standards and is guranteed to work always? |
|
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|
|
Jakob Bieling
Guest
|
| Posted: Wed Jul 12, 2006 9:10 am Post subject: Re: Defining a variable in switch statement |
|
|
Rahul <rahulsharma (AT) lucent (DOT) com> wrote:
| Quote: | Hi,
Is the following correct? Here i have declaread a char array in case
1: and am using the same in case 2:
first I tried another definition of ch in case 2: assuming that if i=2
then char ch[] will not get allocated in case 1:. But the compiler
gave me (re-definition error) so i removed it and now its working
fine.
Is it correct as per the standard?
|
Afaik, no. The initialization of 'ch' might be skipped when 'i' is
2.
| Quote: | switch (i)
{
case 1:
char ch[12];
strcpy(ch, "case 1\n");
cout<<ch;
break;
case 2:
strcpy(ch, "case 2\n"); //Can i use it here, when i=2, why
should the compiler allocate
// the variable shich is
declared in the case which is not true.
cout<<ch;
break;
default:
strcpy(ch, "default\n"); // Is it ok here also?
cout<<ch;
}
|
hth
--
jb
(reply address in rot13, unscramble first) |
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|
|
Forest
Guest
|
| Posted: Wed Jul 12, 2006 9:10 am Post subject: Re: Defining a variable in switch statement |
|
|
It is valid I think. You can just consider *case statement* as a
*label*.
Rahul wrote:
| Quote: | Forest wrote:
You can use { and } to meet your requirement.
[example]
switch ( i )
{
case 1:
{
char ch[1];
//...
break;
}
case 2:
{
char ch[2];
//...
break;
}
//...
}
[end example]
Rahul wrote:
Hi,
Is the following correct? Here i have declaread a char array in case 1:
and am using the same in case 2:
first I tried another definition of ch in case 2: assuming that if i=2
then char ch[] will not get allocated in case 1:. But the compiler gave
me (re-definition error) so i removed it and now its working fine.
Is it correct as per the standard?
switch (i)
{
case 1:
char ch[12];
strcpy(ch, "case 1\n");
cout<<ch;
break;
case 2:
strcpy(ch, "case 2\n"); //Can i use it here, when i=2, why
should the compiler allocate
// the variable shich is
declared in the case which is not true.
cout<<ch;
break;
default:
strcpy(ch, "default\n"); // Is it ok here also?
cout<<ch;
}
That I have done, But I wanted to know is the above behaviour as per
the standards and is guranteed to work always? |
|
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