Thread: something weird

hello today i was trying something with linked list to initialize a var in the 2nd field of the for loop using the , operator but i got into a forever loop i want to know if this is defined behaviour or not ? since 1st field only does stuff once and the 3rd field does it after loop runs

Code:

#include <stdio.h>
int main(void)
{
    int x=1;
    int b;
    for(; x<10  , b=x  ;x++ )
        printf("%d\n",x);
    getchar();
    return 0;
}

you are setting b equal to x, I believe that is an assignment not a comparison. It should always be true correct?

Originally Posted by quzah

What he really should be doing is this:

Code:

for( ; b = x && x < 10; x++ )

Otherwise, it's still not going to break when x is bigger than 9.


Quzah.

i think that wont work since it will evalute to false and wont run the loop i tried it and it didn't run the loop

oke here i got it i think when i puted braces around b=x i think it doesnt makes it get discarded and gets initialized to x then after that test is made

Code:

#include <stdio.h>
int main(void)
{
    int x;
    int b;
    for(x=0; (b=x) , x<10 ;x++)
          printf("%d\n",b);
    getchar();
    return 0;
}

...And now you're back to where you started. Here's an idea: how about not using obscure loop control constructs?

Code:

    for(x = 0; x < 10; x++)
    {
        b = x;
        printf("%d\n",b);
    }

Easy.

Originally Posted by Sebastiani

...And now you're back to where you started. Here's an idea: how about not using obscure loop control constructs?

Code:

    for(x = 0; x < 10; x++)
    {
        b = x;
        printf("%d\n",b);
    }

Easy.

yah i know thats easy :P but i was just curious abt initializing in the middle when i added (b=x) in braces it made it work ..

It wasn't the braces that made it work, it was putting it before the comma.

yes your right it makes sense aswell