How to swap weapons easily?

well if you have all the weapon as a child of the camera (assuming you are making an fps) attach a script to the camera. then you can create a list of GameObjects for your gun that is attach and then enable or disable them.

for example:

 var gun1 : GameObject;
 var gun2 : GameObject;
 
 function Start() {
 gun1.gameObject.SetActive(true);
 gun2.gameObject.SetActive(false);
 }
 
 function Update(){
     if (Input.GetKeyDown("1")){
     gun1.gameObject.SetActive(true);
     gun2.gameObject.SetActive(false);
     }
     else if (Input.GetKeyDown("2")){
     gun1.gameObject.SetActive(false);
     gun2.gameObject.SetActive(true);
     }
 }

this scrip is not the best way to do it and has not been tested so they may be some issues with it but i think you get the point of what im saying.Dont forget to add your inputs 1 and 2 by going into edit -project settings - Input