Adding Item object to Inventory List

Hello all, I have been working on an inventory system for my dungeon crawler. To do this I have been converting JavaScript into C#(as it is what I am using) and I have ran into a bug that I do not know how to solve.

When I press the loot button, it will call the GiveLoot function, but this causes an error and the inventory remains empty. The first piece of code is the class the bug is apparantly in. I will put the error message below it followed by the other code to give a better understanding.

 using UnityEngine;
 using System.Collections;
 
 public class AddItem : MonoBehaviour {
     
     public Inventory Inventory;
     public ItemClass[] loot;
     
     void main()
     {}
     
     void GiveLoot()
     {
         for(int i = 0; i < loot.Length; i++)
         {
     
             this.Inventory.playerInventory.Add(this.loot[i]);
         }
     }
     
     void OnGUI()
     {
         GUILayout.BeginArea(new Rect((float)100, (float)0, (float) 50, (float)50));
         if(GUILayout.Button("Loot", new GUILayoutOption[0]))
         {
             this.GiveLoot();
         }
         GUILayout.EndArea();
     }
     
     // Use this for initialization
     void Start () 
     {
         this.Inventory = this.GetComponent("Inventory")as Inventory;
     }
     
     
 }

The error message(line 17):

NullReferenceException: Object reference not set to an instance of an object AddItem.GiveLoot () (at Assets/Inv Sys/script/AddItem.cs:17) AddItem.OnGUI () (at Assets/Inv Sys/script/AddItem.cs:26)

Now the Inventory:

 using UnityEngine;
 using System.Collections;
 using System.Collections.Generic;
 
 public class Inventory : MonoBehaviour {
     
     public bool equipped;
     public ItemClass equippedItem;
     public Transform playerHand;
     public List<ItemClass> playerInventory = new List<ItemClass>();
     public Vector2 scrollView;
     
     // Use this for initialization
     void Start () {
     
     }
     
     // Update is called once per frame
     void Update () 
     {
         if(this.equippedItem.itemType.Equals(ItemClass.ItemType.Weapon))
             this.equipped = true;
         else
             this.equipped = false;
     }
     
     
     void OnGUI()
     {
         GUILayout.BeginArea(new Rect ((float) (Screen.width - 500), (float)0, (float)500, (float)500));
         GUILayoutOption[]optionArray1 = new GUILayoutOption[] {GUILayout.Width((float)500), GUILayout.Height((float)500)};
         this.scrollView = GUILayout.BeginScrollView(this.scrollView, optionArray1);
         for(int i = 0; i < this.playerInventory.Count; i++)
         {
             GUILayout.BeginHorizontal(new GUILayoutOption[0]);
             
             if(GUILayout.Button(this.playerInventory[i].icon, new GUILayoutOption[0]) 
                 &&(this.playerInventory[i].itemType.Equals(ItemClass.ItemType.Weapon))
                 && !this.equipped)
             {
                 this.equippedItem = this.playerInventory[i];
                 Transform thing;
                 thing = (Transform)Object.Instantiate(this.playerInventory[i].itemPrefab, this.playerHand.position, Quaternion.identity);
                 thing.parent = this.playerHand;
                 this.playerInventory.RemoveAt(i);
                 return;
             }
             
             GUILayout.Box(this.playerInventory[i].name, new GUILayoutOption[0]);
             GUILayout.EndHorizontal();
             GUILayout.Box(this.playerInventory[i].description, new GUILayoutOption[0]);
         }
         
         GUILayout.EndScrollView();
         GUILayout.EndArea();
         
         if(GUI.Button(new Rect((float)((Screen.width / 2) - 0x19), (float)(Screen.height - 50), (float) 50, (float) 50), this.equippedItem.icon) && this.equipped)
         {
             this.playerInventory.Add(this.equippedItem);
             Object.Destroy(GameObject.FindGameObjectWithTag("Weapon"));
             this.equippedItem = new ItemClass();
         }    
             
     }
     
     
 }

Sorry for the length of the post, if you can help me at all I would really appreciate it. Any other questions please ask and I will let you know.

Thanks again and have a nice day :)