Formal Arguments (1)

Consider

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

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

• what's the value of j after calling f() ?

• C passes arguments by value, thus j and k are left unchanged

• i , x and a are formal arguments and in the scope of f()

• upon calling f() , it is as if the compiler generated code to initialize the arguments

        int i = j;
        float x = k;    /* note type conversion */
        float *a = y;   /* initialize pointer to array */
  

• thus y[0] does get set to 0.0