How to avoid this NullPointerException

Question

I\'m working on a small arcade video game, and I am looking to double buffer to improve animation. I have one class that\'s supposed to draw the blank image, and another class t

Answer 1

Since MC extends render, the dbg you are referring to belongs to the MC instance that called draw. You can fix it by calling

render.dbg.drawLine( 100, 100, 200, 200 );

or take advantage of the inheritance you implemented

class MC extends Render {
    //MC is a render, so you don't need to create another one
    public void draw() {
        gameRender(); //Call the MC's own gameRender
        dbg.drawLine( 100, 100, 200, 200 );  //Calling gameRender initialized dbg so you won't get a NullPointerException
    }
}