Question

I am trying to understand how pointer incrementing and dereferencing go together, and I did this to try it out:

#include <stdio.h>
int main(int argc, char *argv[])
{
    char *words[] = {"word1","word2"};
    printf("%p\n",words);
    printf("%s\n",*words++);
    printf("%p\n",words);
    return 0;
}

I expected this code to do one of these:

1. First dereference then increase the pointer (printing word1)
2. First dereference then increase the value (printing ord1)
3. Dereference pointer + 1 (printing word2)

But compiler won’t even compile this, and gives this error: lvalue required as increment operand am I doing something wrong here?

Answer 1

You cannot increment an array, but you can increment a pointer. If you convert the array you declare to a pointer, you will get it to work:

#include <stdio.h>
int main(int argc, char *argv[])
{
    const char *ww[] = {"word1","word2"};
    const char **words = ww;
    printf("%p\n",words);
    printf("%s\n",*words++);
    printf("%p\n",words);
    return 0;
}