Swap and cycle through game objects using an array

I am trying to swap and cycle through game objects. I have an array of game objects that are projectile attacks. I want the user to be able to press a button and swap out the current three game objects with the next three game objects in the array. When the last three are reached, I want to start the cycle over again. Basically it is like switching weapon loadouts on the fly. I have tried a few ways to do this (my switch statement failed horribly), but none have worked so far. Now I am running low on ideas. Any suggestions/tips/hints for how to handle something like this will be extremely helpful. Below is some code to look at if it helps you to get an idea of what I am trying to do.

using UnityEngine;
using System.Collections;

public class Shoot : MonoBehaviour {
	public GameObject[] attackArray = new GameObject[6];
	public int shotPosX;
	public int shotPosY;

	// Use this for initialization
	void Start () {
	// Update is called once per frame
	void Update () {
		GameObject attack = attackArray[0];
		GameObject attackDown = attackArray[1];
		GameObject attackUp = attackArray[2];
		if(Input.GetButtonUp("Fire1") == true)
			Instantiate(attack, new Vector3(transform.position.x + shotPosX, transform.position.y - shotPosY, transform.position.z), transform.rotation);
		if(Input.GetButtonUp("Fire2") == true)
			Instantiate(attackUp, transform.position, transform.rotation);
		if(Input.GetButtonUp("Fire3") == true)
			Instantiate(attackDown, transform.position, transform.rotation);

This wont compile :stuck_out_tongue: But should be a reasonable way of doing it. You could ofcourse also just have 3 arrays, 1 for each weapon “slot?”.

int collectionSet = 0; // When zero the first three gameobjects in your array will be used as fire 1,2,3...
public GameObject[] attackArray = new GameObject[6];

update ()()()()(

if(hit button that switches set of weapons)
  if(collectionSet is attackArray.Length - 2)
     collectionSet = 0;
     collectionSet += 3;

if( hit fire1)
Instantiate(attack[collectionSet] // attack.... // etc....
if( hit fire2)
Instantiate(attack[collectionSet + 1] // attackUp.... // etc....
if( hit fire3)
Instantiate(attack[collectionSet + 2] // attackDown.... // etc....