How do I make a bullet fire? - actionscript-3

Question

I don't know what to do next.
Right now when I click, it adds the bullet and rotates it to the correct angle, but I don't know how to make it fire. I want to have the bullet shoot to where the mouse is pointing. Thanks!
PS: Sorry if the code is messy.
package
{
import flash.display.MovieClip;
import flash.display.Sprite;
import flash.events.Event;
import flash.events.TimerEvent;
import flash.events.KeyboardEvent;
import flash.utils.Timer;
import flash.text.Font;
import flash.events.MouseEvent;
import flash.text.TextDisplayMode;
import flash.text.TextExtent;
import flash.text.TextField;
import flash.text.TextFormat;
import fl.motion.easing.Back;
import flash.display.DisplayObject;
public class GameEnter extends MovieClip
{
public var _bullet:bullet;
public function GameEnter()
{
stage.addEventListener(MouseEvent.MOUSE_DOWN, shootBullet);
stage.addEventListener(MouseEvent.MOUSE_UP, removeBullet);
}
public function init()
{
_bullet = new bullet();
addChild(_bullet);
_bullet.x = stage.stageWidth / 2;
_bullet.y = stage.stageHeight / 2;
addEventListener(Event.ENTER_FRAME, onEnter);
}
public function onEnter(event:Event)
{
var dx:Number = mouseX - _bullet.x;
var dy:Number = mouseY - _bullet.y;
var angle:Number = Math.atan2(dy,dx) * 180 / Math.PI;
_bullet.rotation = angle;
}
public function shootBullet(event:MouseEvent)
{
init();
}
public function removeBullet(event:MouseEvent)
{
removeChild(_bullet);
}
}
}

Answer 1

To move an object in a direction based on rotation, you'll need cos and sin.
Math.cos() and Math.sin() only accept radians, so you'll need to convert rotation to radians like you have for Math.atan2() in your example.
Sample:
// Note: Utilising the property 'angle' from your code.
_bullet.x += Math.cos(angle);
_bullet.y += Math.sin(angle);
And then obviously multiply these values by a value that will represent how fast you want the bullet to go, eg:
var velocity:Number = 10.5;
_bullet.x += Math.cos(angle) * velocity;
_bullet.y += Math.sin(angle) * velocity;