Ambiguous behavior of variable declaration in c

Question

i have the following code

#include<stdio.h>
int main()
{
    int a12345678901234567890123456789012345;
    int a123456789012345678901234567890123456;
    int sum;

    scanf("%d",&a12345678901234567890123456789012345);
    scanf("%d",&a123456789012345678901234567890123456);
    sum = a12345678901234567890123456789012345 + a123456789012345678901234567890123456;
    printf("%d\n",sum);

    return 0;
}

the problem is, we know that ANSI standard recognizes variables upto 31 characters...but, both variables are same upto 35 characters...but, still the program compiles without any error and warning and giving correct output...
but how?
shouldn't it give an error of redeclaration?

Answer 1

Many compilers are built to exceed ANSI specification (for instance, in recognizing longer than 31 character variable names) as a protection to programmers. While it works in the compiler you're using, you can't count on it working in just any C compiler...