Fire multiple bullets but when i put the looping i get error (access of undefined property shot)

you're making shot local to fire() and losing your reference.

use:

var shotA:Array=[]; stage.addEventListener(Event.ENTER_FRAME,looping); function looping (event:Event):void { for(var i:int=shotA.length-1;i>=0;i--){   shotA.x +=10; if(shotA.x>stage.stageWidth){ shotA.splice(i,1); } } } fire_btn.addEventListener(MouseEvent.CLICK,fire); function fire(MouseEvent:Event):void {   var shot:bullet = new bullet(); shotA.push(shot);   this.addChild(shot);   shot.x = player.x;   shot.y = player.y; }