Could you explain how the output is `-4`? I think `++pp;` is UB but not sure. Your explanation will really help in the way of understanding. Could be there any difference of outputs in big-endian or little-endian machine?

```
#include <stdio.h>

int a[] = { -1, -2, -3, -4 };
int b[] = { 0, 1, 2, 3 };

int main(void)
{
    int *p[] = { a, b };
    int **pp = p;
    printf("a=%p, b=%p, p=%p, pp=%p\n", (void*)a, (void*)b, (void*)p, (void*)pp);
    ++pp;
    printf("p=%p, pp=%p *pp=%p\n", (void*)p, (void*)pp, (void*)*pp);
    ++*pp;
    printf("p=%p, pp=%p *pp=%p\n", (void*)p, (void*)pp, (void*)*pp);
    ++**pp;

    printf("%d\n", (++**pp)[a]);
}

```

My output:

```
a=0x107121040, b=0x107121050, p=0x7ffee8adfad0, pp=0x7ffee8adfad0
p=0x7ffee8adfad0, pp=0x7ffee8adfad8 *pp=0x107121050
p=0x7ffee8adfad0, pp=0x7ffee8adfad8 *pp=0x107121054
-4

```

[Ideone output](http://www.ideone.com/6xzVQT)