Why does this small C program crash?

Question

The program is:

#include 
#include 
int main(void) {
    char *a=\"abc\",*ptr;
    ptr=a;
    ptr++;
    *ptr=\'k\';
    printf(\"         


        

Answer 1

Because "abc" is a constant string literal. Then you point ptr to it and try to modify it which is undefined behaviour. Typically string literals are put in a memory section which gets mapped as read-only - hence the access violation.

See also this question: String literals: Where do they go?