Reverse a string using a recursive function

Question

I am currently studying C and I can\'t get past this exercise. I must create a recursive function to reverse string1 into string2. Here is my code. I w

Answer 1

in-place (the caller could make a copy of the string before calling this function) string reverse with tail-recursion

void reverse (char *str, size_t len)
{
  char tmp;
  if (len-- < 2) return;

  tmp = *str;
  *str = str[len];
  str[len] = tmp;

  reverse (str+1, len -1);
}

O, if you don't want pointers:

void reverse (char str[], size_t len)
{
  char tmp;
  if (len-- < 2) return;

  tmp = str[0];
  str[0] = str[len];
  str[len] = tmp;

  reverse (str+1, len -1);
}