actionscript circle entire drawing moves why? - actionscript

Question

package {
import flash.display.Sprite;
import flash.events.Event;
import flash.events.KeyboardEvent;
import flash.ui.Keyboard;
public class helloworld extends Sprite {
public static var x:int = 0;
public static var y:int = 0;
public function helloworld() {
graphics.lineStyle(1, 0, 1);
stage.focus = this;
stage.addEventListener(KeyboardEvent.KEY_DOWN, onKeyDown);
}
private function onKeyDown(event:KeyboardEvent):void {
if (event.keyCode == Keyboard.DOWN)
{
y++;
graphics.moveTo(x,y);
graphics.drawCircle(x, y, 10);
}
if (event.keyCode == Keyboard.RIGHT)
{
x++;
graphics.moveTo(x,y);
graphics.drawCircle(x, y, 10);
}
}
}
The circles that are drawn first also move. How can I stop it from doing that?

Answer 1

You think you're using your public static x & y values, but actually you're using the Sprite's built in x and y properties which control its location on the stage. When you use y++ and x++ it moves the entire sprite down/right.
You should either make sure you're always calling helloworld.x && helloworld.y (bad idea, easy to forget).
OR
You should not use variables named x and y. Try: circleX and circleY or something that is more descriptive of what you're using it for.