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C pointer arithmetic example

*p++

Dereferences the value of p, then increments it

int a[] = {1, 2, 3, 4};
int *p = a

int x = *p++; // x = 1, p then point to 2

*--p dereferences then increments

*++p

Increments the pointer then dereferences it

int a[] = {1, 2, 3, 4};
int *p = a

int x = *++p; // x = 2, p point to 2

*--p decrements then dereferences

(*++p)[i]

In the context of pointers to pointers, like argv[].

1. ++p increment the pointer
2. *++p dereferences the pointer, accessing the pointer it points to
3. (*++p)[i] access the ith element of the array

// by calling the program with: ./program -n hello
char c = (*++argv)[0] // move the pointer to the second command line argument '-n', and accesses its first char '-'

Equivalent to **++p

*++p[i]

In the context of pointers to pointers, like argv[].

1. p[i] get the ith pointer of the pointers array ([] is evaluated before *++)
2. ++p[i] increments the ith pointer
3. *++p[i] dereferences the ith element of the array

// by calling the program with: ./program -n hello
char c = *++argv[1] // access the argv[1] command line argument '-n' as a pointer, increment the pointer (now points at 'n', because first it was on '-'), access the value 'n'