Function parameter question

[Penanito]

I was doing some more tutorials and i found this function declaration (inside of a class):

  void render( int x, int y, SDL_Rect* clip = NULL, double angle = 0.0, SDL_Point* center = NULL, SDL_RendererFlip flip = SDL_FLIP_NONE );

yet when the function is called it only gives 2 values

classObject.render( ( SCREEN_WIDTH - gStartPromptTexture.getWidth() ) / 2, 0 );

I noticed that only the 2 ints the parameter asks for (int x, int y) are undeclared, the rest are declared to 0 or null or so on. so my question is:

When calling a function, you only need to pass the parameter values that are undeclared?

[long double main]

In your example above, clip, angle, center, and flip are called default parameters, since they have default values provided for them.

If you don't provide a value for them, the compiler will use those default values.

Also see http://www.cplusplus.com/doc/tutorial/functions/ (scroll down to "Default values in parameters").

[Penanito]

Read that page and somehow managed to miss that part, exactly answers my question though, thanks ^^