const Function Argument

Consider

      void f (int i, float x, const float *a)
      {
        i = 100;
        x = 101.0 * a[0];    /* OK */
        a[0] = 0.0;          /* WRONG */
      }

      int main ()
      {
        int j = 1;
        int k = 2;
        float y[] = {3.0, 4.0, 5.0};
        . . .
        f (j, k, y);
        . . .
      }

• a const argument tells user of function that his data wouldn't be changed

• the const is enforced when attempting to compile function