for(int x

Sorry for such a basic question. I use the following code all the time:

Code:

for (int x=0;cond;expr) {
 ....
}

ie. The var x is initialised in the loop starter. A search on this board and comp.lang.c also shows thousands of instances of code like this.
However, when I do a lint check with this online lint checker:
http://www.cleanscape.net/products/l...ine/login.html
It gives me errors such as:

Code:

	for (int sectionIndex = 0;sectionIndex < 3;sectionIndex++) {
	     ^
mx.c: line 153: Error # 33: Expression expected.

---------------------------------------------------------------------

	for (int sectionIndex = 0;sectionIndex < 3;sectionIndex++) {
	         ^
mx.c: line 153: Warning # 102: Strange use of "for" statement.
>   The  statement  in question is  of a form which may reflect some
>   sort of typing error; for example, the statement:
>   for (i = 0; i < 10; j++) { ... }
>   should be incrementing "i", not "j".

---------------------------------------------------------------------

	for (int sectionIndex = 0;sectionIndex < 3;sectionIndex++) {
	         ^
mx.c: line 153: Error # 26: ';' expected.

---------------------------------------------------------------------

	for (int sectionIndex = 0;sectionIndex < 3;sectionIndex++) {
	         ^
mx.c: line 153: Error # 21: Undefined symbol: sectionIndex

Is initialising a var like this not ansi or is this lint checker got problems. If it is not ansi, is there any compilers that do not support it?

for (int x=0;cond;expr)

This is C++ code, not C. In C you cannot declare variables in the first step of the for loop. Valid code is:

int x;
for( x = 0; cond; expr )


Quzah.

Thanks a lot.

I understand that it is legal in the c99 standard.? It seems from the quantity of code that contains this syntax that many compilers support it, ansi or not. Mine (lcc-win) does not complain even with the ansic option on.

Anyway, I better start fixing my code. I also have to remove // coments from my code. If neither of these are legal it would be nice if there wasn't so much sample code/tutorials etc. that contain them.

Thanks again.

Hmm... well... at least I won't go making that mistake... heh... I can learn just by watching these threads.

I've used for (int x=0;x<50;x++) quite a lot, but I guess I'll have to stop.

Originally posted by Frobozz
Hmm... well... at least I won't go making that mistake... heh... I can learn just by watching these threads.

Well you'd like to think so anyway. You just have to watch out for the threads where people in insist they're right even when everyone on earth is telling them they're wrong.

Some people just can't admit they're wrong.

Quzah.

Thanks all!

Code:

for (int p = 4;p;p--) {
  ...
}
int p;

I gather that C99 alllows the initialisation of variables anywhere. However I gather that no special scope is given when initialised in the for starter. So the above would still be illegal. Is this the same in c++ or does p get the scope of the for block in c++?

Thanks.

I also found many problems in this way.
Even gcc3.2 doesn't support for(int i=...;cond;expr).
So I use c++ compiler, then.

you have to compile with the -std=c99 flag

I have tested, it works very well with gcc3.2, thanks