Shuffling Items in Unity 3D

Question

I have this script of an array that shows a listing of items.

Now the thing is I only want this list to have five items shown out of ten and also shuffled, so you can't have the same list every time you start a new game

I was thinking if there should be a Random.Range implemented but I don't know where.

Please Help, and explain what should be done. I'm still a bit new to this and Thanks.

Here's the script:

using UnityEngine;
using System.Collections;
using System.Collections.Generic;

public class RayCasting : MonoBehaviour
{
    public float pickupDistance;
    public List<Item> items;

    #region Unity
    void Start ()
    {
        Screen.lockCursor = true;
    }

    void Update ()
    {
        RaycastHit hit;
        Ray ray = new Ray(transform.position, transform.forward);
        if (Physics.Raycast(ray, out hit, pickupDistance))
        {
            foreach(Item item in items)
            {
                if(Input.GetMouseButtonDown(0)) 
                {
                    if (item.gameObject.Equals(hit.collider.gameObject))
                    {
                        numItemsCollected++;
                        item.Collect();
                        break;
                    }
                }
            }
        }
    }

    void OnGUI()
    {
        GUILayout.BeginArea(new Rect(130,400,100,100));
        {
            GUILayout.BeginVertical();
            {
                if (numItemsCollected < items.Count)
                {
                    foreach (Item item in items)
                    {
                        GUILayout.Label(string.Format("[{0}] {1}", item.Collected ? "" + item.password: " ", item.name ));
                    }
                }
                else
                {
                    GUILayout.Label("You Win!");
                }
            }
            GUILayout.EndVertical();
        }
        GUILayout.EndArea();
    }
    #endregion

    #region Private
    private int numItemsCollected;
    #endregion
}

[System.Serializable]
public class Item
{
    public string name;
    public GameObject gameObject;
    public int password;

    public bool Collected { get; private set; }

    public void Collect()
    {
        Collected = true;
        gameObject.SetActive(false);
    }

    public void passwordNumber()
    {
        password = 0;
        Collected = true;
        gameObject.SetActive(false);
    }
}

Answer 1

I assume you'll want to leave items intact without removing any Items, so I'd suggest creating a second List called finalItems, which will contain your 5 random Items.

public List<Item> items;
public List<Item> finalItems;

#region Unity
void Start ()
{
    Screen.lockCursor = true;

    // Do a while loop until finalItems contains 5 Items
    while (finalItems.Count < 5) {
        Item newItem = items[Random.Range(0, items.Count)];
        if (!finalItems.Contains(newItem)) {
            finalItems.Add(newItem);
        }
    }
}

And then in your foreach statements, loop through finalItems instead of items.

This will give you 5 random Items every game!