Hi All,
I have one question regarding the conditional operator.
In the draft C99 standard it is mentioned that
"1 The following are the sequence points described in 5.1.2.3:
-- The call to a function, after the arguments have been evaluated
(6.5.2.2).
-- The end of the first operand of the following operators: logical AND
&& (6.5.13);
logical OR || (6.5.14); conditional ? (6.5.15); comma , (6.5.17)."
My question is conditional operator consist of "?" and ":" . Now if
I try to modify the value of one particular variable between "?" and
": " will it show undefined behavior?
For example
b = (a++)? a++: a++;
Here is the second increment of a++ will be undefined?
Regards,
Somenath
3  2436 
somenath wrote:
I have one question regarding the conditional operator.
In the draft C99 standard it is mentioned that
"1 The following are the sequence points described in 5.1.2.3:
-- The call to a function, after the arguments have been evaluated
(6.5.2.2).
-- The end of the first operand of the following operators: logical AND
&& (6.5.13);
logical OR || (6.5.14); conditional ? (6.5.15); comma , (6.5.17)."
My question is conditional operator consist of "?" and ":"
Well, no, it has three expressions in there also: `test ? ifso : ifnot`.
There's a sequence point after the first operand, ie, `test`. The second
(or third) operand is [as if it is] evaluated once the test is completed.
. Now if
I try to modify the value of one particular variable between "?" and
": " will it show undefined behavior?
For example
b = (a++)? a++: a++;
Here is the second increment of a++ will be undefined?
No. Why do you think it might be?
--
Chris "see Quen's point?" Dollin
Hewlett-Packard Limited Cain Road, Bracknell, registered no:
registered office: Berks RG12 1HN 690597 England
On Dec 14, 3:19 pm, Chris Dollin <chris.dol...@hp.comwrote:
somenath wrote:
I have one question regarding the conditional operator.
In the draft C99 standard it is mentioned that
"1 The following are the sequence points described in 5.1.2.3:
-- The call to a function, after the arguments have been evaluated
(6.5.2.2).
-- The end of the first operand of the following operators: logical AND
&& (6.5.13);
logical OR || (6.5.14); conditional ? (6.5.15); comma , (6.5.17)."
My question is conditional operator consist of "?" and ":"
Well, no, it has three expressions in there also: `test ? ifso : ifnot`.
There's a sequence point after the first operand, ie, `test`. The second
(or third) operand is [as if it is] evaluated once the test is completed.
. Now if
I try to modify the value of one particular variable between "?" and
": " will it show undefined behavior?
For example
b = (a++)? a++: a++;
Here is the second increment of a++ will be undefined?
No. Why do you think it might be?
Sorry for posting the same question twice.
In the standard it specifically says about "conditional ? (6.5.15);"
So I had the doubt that is it true for ":" also ?
"somenath" <so*********@gmail.comschrieb im Newsbeitrag
news:31**********************************@s8g2000p rg.googlegroups.com...
On Dec 14, 3:19 pm, Chris Dollin <chris.dol...@hp.comwrote:
>somenath wrote:
I have one question regarding the conditional operator.
In the draft C99 standard it is mentioned that
"1 The following are the sequence points described in 5.1.2.3:
-- The call to a function, after the arguments have been evaluated
(6.5.2.2).
-- The end of the first operand of the following operators: logical AND
&& (6.5.13);
logical OR || (6.5.14); conditional ? (6.5.15); comma , (6.5.17)."
My question is conditional operator consist of "?" and ":"
Well, no, it has three expressions in there also: `test ? ifso : ifnot`.
There's a sequence point after the first operand, ie, `test`. The second
(or third) operand is [as if it is] evaluated once the test is completed.
. Now if
I try to modify the value of one particular variable between "?" and
": " will it show undefined behavior?
For example
b = (a++)? a++: a++;
Here is the second increment of a++ will be undefined?
No. Why do you think it might be?
Sorry for posting the same question twice.
In the standard it specifically says about "conditional ? (6.5.15);"
So I had the doubt that is it true for ":" also ?
It seem irrelevant whether ":" is a sequence point, it does separate the
"if" from the "else" branch, so only one of the statements get
executed/evaluated anyway. Then finally the ; gets hit, which again is a
sequence point.
Bye, Jojo This thread has been closed and replies have been disabled. Please start a new discussion. Similar topics
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