can anyone show me the problem of the below code?it show segmentation fault.my idea is to let user input number to define the size of the array. please help!
Code:#include<stdio.h> main() { int a; int *i; int array[*i]; int j; scanf("%d",&j); i=&j; scanf("%d",&array[0]); printf("%d\n",array[0]); }
You can't do that with static memory.
You need to malloc.
1. Get rid of gets(). Never ever ever use it again. Replace it with fgets() and use that instead.
2. Get rid of void main and replace it with int main(void) and return 0 at the end of the function.
3. Get rid of conio.h and other antiquated DOS crap headers.
4. Don't cast the return value of malloc, even if you always always always make sure that stdlib.h is included.
You can. Just not the way he's trying to. C99 allows for variable length arrays.That's why you're seg-faulting.Code:#include<stdio.h> main() { int a; int *i; <-- doesn't point at anything specific int array[*i <-- dereferencing random spot in memory ]; int j; scanf("%d",&j); i=&j; scanf("%d",&array[0]); printf("%d\n",array[0]); }
Quzah.
Hope is the first step on the road to disappointment.
Interesting. I think I saw that a few times and thought it was something non compliant with the standard.Originally Posted by quzah
1. Get rid of gets(). Never ever ever use it again. Replace it with fgets() and use that instead.
2. Get rid of void main and replace it with int main(void) and return 0 at the end of the function.
3. Get rid of conio.h and other antiquated DOS crap headers.
4. Don't cast the return value of malloc, even if you always always always make sure that stdlib.h is included.
Hi Cladiu...
This is legal in c99...
What our friend was trying, with an uninitialized pointer could result in an array gigabytes in size.Code:int x = 30; int field[x];
Yes, I realized that his code was completely wrong.
I have seen things like int field[n] before but I guess because I have been taught C in the stone age, I am not always aware of these fancy C99 things.
1. Get rid of gets(). Never ever ever use it again. Replace it with fgets() and use that instead.
2. Get rid of void main and replace it with int main(void) and return 0 at the end of the function.
3. Get rid of conio.h and other antiquated DOS crap headers.
4. Don't cast the return value of malloc, even if you always always always make sure that stdlib.h is included.
I tell ya, these new fangled inventions will be the death of me yet!Yes, I realized that his code was completely wrong.
I have seen things like int field[n] before but I guess because I have been taught C in the stone age, I am not always aware of these fancy C99 things
I learned C on a C-99 platform (moving over from Pascal) but didn't know about this until I saw it here... go figger.
thanks all you guy. i got it now.
