Why is this not valid in C (Arrays)?

Question

#include<stdio.h>
int main(){
    int n;
    printf("Enter a value for n\n");
    scanf("%d",&n);
    int A[n];
}

Why can't I assign the size of an array explicitly from a user?

Variable-length arrays are in C99. Maybe you're using an older compiler? — Barmar, Oct 25 '17 at 16:19
It would also possibly be an issue if OP is using C11, depending on the compiler, as VLA support was made optional. — Christian Gibbons, Oct 25 '17 at 16:46

Doncho Gunchev · Answer 1 · 2017-10-25T17:14:34.080

-1

There is VLA support in C99 and C11 (optional). With GCC 7.2.1 your example works. I compiled like this:

gcc abc.c -o abc

gcc --std=c99 abc.c -o abc

Looks like your compiler does not support this feature.

edited Oct 25 '17 at 17:14

answered Oct 25 '17 at 16:26

Doncho Gunchev

1

C/C++ is not a language. This is a C question so answers relating to C++ constructs are off topic. Furthermore, C99 supports Variable Length Arrays, and C11 has optional support for VLAs. – Christian Gibbons Oct 25 '17 at 16:44
You are correct. C++ does not, C11 does.. will fix the answer shortly... – Doncho Gunchev Oct 25 '17 at 17:03

1 Answers1