[C++ Question] For loop Multiple Initialization

[charlie.xia.fdu]

Hi C++ users,

for(int i=0,int j=10 ; i<5&&j<10 ; i++ , j--) {}

example from: http://www.tech-faq.com/iterations.shtml
Is not valid in my eclipse cdt.
Is there multiple initialization in C++? How can we use that?

Thanks!

Charlie

[charlie]

On Nov 7, 1:08*am, blargg....@gish puppy.com (blargg) wrote:

charlie.xia.... @gmail.com wrote:

On Nov 4, 2:20 am, Pete Becker <p...@versatile coding.comwrote :

On 2008-11-03 23:03:16 -0500, blargg....@gish puppy.com (blargg) said:
Pawel Dziepak wrote:
charlie.xia.... @gmail.com wrote:
>for(int i=0,int j=10 ; i<5&&j<10 ; i++ , j--) {}

>example from:http://www.tech-faq.com/iterations.shtml
>Is not valid in my eclipse cdt.
>Is there multiple initialization in C++? How can we use that?

That way is correct:

for (int i=0, j=10; i<5 && j<10; i++, j--) {}

Unless I'm wrong, there's no way to initialize variables of different
types in that part of for loop.

I'll probably regret this, but I believe you can:

* * double d;
* * int* p;
* * for ( char c = (d = 1.234, p = new int, 'X'); ...

Or, less cryptically,

double d;
int *p;
char c;
for (c = 'X', d = 1.234, p = new int; ...

Now, technically, that's not initialization, but it may well be what
was actually meant.

But actually I want these variables only in the scope of for loop.
Keep the initialization and increment in the for statement is the only
neat way I can think of.
Isn't it?

The for loop is for common loops that have a single variable that is
initialized, tested, and advanced. If it were made to handle every
possible loop, it would lose its usefulness. In fact, such a more general
loop construct already exists as a combination of a compound statement
({}) with a while or do-while loop in it. What do you gain by trying to
jam complicated things into a for loop anyway?

Also, please don't top-post, and don't quote signatures (see
<http://www.netmeister. org/news/learn2quote.htm l>).

Good to know. Thanks all.