Array randomise example.

DeckShuffle.cs

 using UnityEngine;
 using System.Collections;
 
 // taken from https://answers.unity.com/questions/1189736/im-trying-to-shuffle-an-arrays-order.html
 
 public class DeckShuffle : MonoBehaviour {
 
     public GameObject[] decklist;
     private GameObject tempGO;
     
     void Start () {
         Shuffle();
     }
     
     public void Shuffle() {
         for (int i = 0; i < decklist.Length; i++) {
             int rnd = Random.Range(0, decklist.Length);
             tempGO = decklist[rnd];
             decklist[rnd] = decklist[i];
             decklist[i] = tempGO;
         }
     }
 }