### 11.4 The Void Type ¶

The data type `void` is a dummy—it allows no operations. It really means “no value at all.” When a function is meant to return no value, we write `void` for its return type. Then `return` statements in that function should not specify a value (see `return` Statement). Here’s an example:

    void
    print_if_positive (double x, double y)
    {
      if (x <= 0)
        return;
      if (y <= 0)
        return;
      printf ("Next point is (%f,%f)\n", x, y);
    }

A `void`-returning function is comparable to what some other languages (for instance, Fortran and Pascal) call a “procedure” instead of a “function.”