look the error is : Assets\scripts\InventorySystem.cs(84,25): error CS0839: Argument missing

and i know only 3 Arguments and here is the code:

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4.  
5. public class InventorySystem : MonoBehaviour
6. {
7.  
8.    public static InventorySystem Instance { get; set; }
9.     public GameObject inventoryScreenUI;
10.  
11.     public bool isOpen;
12.  
13.     public List<GameObject> slotList = new List<GameObject>();
14.  
15.     public List<string> itemList = new List<string>();
16.  
17.     private GameObject itemToAdd;
18.  
19.     private GameObject whatSlotToEquip;
20.  
21.     //public bool isFull;
22.     private void Awake()
23.     {
24.         if (Instance != null && Instance != this)
25.         {
26.             Destroy(gameObject);
27.         }
28.         else
29.         {
30.             Instance = this;
31.         }
32.     }
33.  
34.     void Start()
35.     {
36.      
37.         isOpen = false;
38.  
39.         PopulateSlotList();
40.  
41.  
42.        
43.     }
44.  
45.         // it makes it so i dont need to drag and drop the slots to the slotlist [DOES WORK NOW]
46.     private void PopulateSlotList()
47.     {
48.        foreach (Transform child in inventoryScreenUI.transform)
49.        {
50.  
51.           if (child.CompareTag("Slot"))
52.           {
53.            Debug.Log("slotlist is working");
54.              slotList.Add(child.gameObject);
55.           }
56.        }
57.     }
58. // makes it so i can open the inventory
59.     void Update()
60.     {
61.         if (Input.GetKeyDown(KeyCode.E) && !isOpen)
62.         {
63.             Debug.Log("E is pressed");
64.             Cursor.lockState = CursorLockMode.None;
65.             inventoryScreenUI.SetActive(true);
66.             isOpen = true;
67.         }
68.         else (Input.GetKeyDown(KeyCode.E) && isOpen);
69.         {
70.             Cursor.lockState = CursorLockMode.Locked;
71.             inventoryScreenUI.SetActive(false);
72.             isOpen = false;
73.         }
74.  
75.          AddToInventory(,itemName);
76.         {
77.  
78.                isFull = true;
79.      
80.                 Debug.Log("inventory is full");
81.          whatSlotToEquip = FindNextEmptySlot();
82.  
83.          itemToAdd = Instantiate(Resources.Load<GameObject>(itemName), whatSlotToEquip.transform.position, whatSlotToEquip.transform.rotation);
84.          itemToAdd.transform.SetParent(whatSlotToEquip.transform);
85.  
86.          itemList.Add(itemName);
87.          
88.          
89.        
90.          
91.         }
92.     }
93.  
94.     public bool CheckIsFull()
95.     {
96.  
97.         isFull =true;
98.  
99.        int counter = 0;
100.  
101.        foreach (GameObject slot in slotList)
102.        {
103.           if (slot.transform.childCount >0)
104.           {
105.              counter == 1;
106.           }
107.  
108.        }
109.        if (counter == 21)
110.           {
111.              return true;
112.           }
113.           else
114.           {
115.               return false;
116.           }  
117.     }
118.  
119.     private GameObject FindNextEmptySlot()
120.     {
121.      
122.        foreach(GameObject slot in slotList)
123.        {
124.          Debug.Log("2");
125.           if (slot.transform.childCount == 0)
126.           {
127.             Debug.Log("working 2");
128.              return slot;
129.           }
130.        }
131.  
132.        return new GameObject();
133.     }
134. }
135.  

 

the error is: AddToInventory(,itemName);

 

what is even a Argument?

 

An argument is a piece of information that you can pass to something, in this case, it looks to be some kind of method.

But looking at your code it seems like you're trying to create a method instead of use one, and inside of another method no less. You're missing a return type too.

This:

Code (CSharp):

1. AddToInventory(,itemName);
2.         {
3.             ...
4.         }

Should be this:

Code (CSharp):

1. void AddToInventory(string itemName)
2.         {
3.             ...
4.         }

What I did:
- Added void to the start to declare this as a method with no return type
- Added a type to the parameter 'itemName'
- Removed rogue comma
- Removed a semi-colon from the end of your method declaration.

And it should not be declared within another method like it is now.

 

Just so you know, if you're still asking questions such as:

Then you're going to have a really really hard time making something as complicated as an inventory or shop system. Inventories are fairly tricky hairy beasts, definitely deep in advanced coding territory.

They contain elements of:

- a database of items that you may possibly possess / equip
- a database of the items that you actually possess / equip currently
- perhaps another database of your "storage" area at home base?
- persistence of this information to storage between game runs
- presentation of the inventory to the user (may have to scale and grow, overlay parts, clothing, etc)
- interaction with items in the inventory or on the character or in the home base storage area
- interaction with the world to get items in and out
- dependence on asset definition (images, etc.) for presentation

Just the design choices of an inventory system can have a lot of complicating confounding issues, such as:

- can you have multiple items? Is there a limit?
- if there is an item limit, what is it? Total count? Weight? Size? Something else?
- are those items shown individually or do they stack?
- are coins / gems stacked but other stuff isn't stacked?
- do items have detailed data shown (durability, rarity, damage, etc.)?
- can users combine items to make new items? How? Limits? Results? Messages of success/failure?
- can users substantially modify items with other things like spells, gems, sockets, etc.?
- does a worn-out item (shovel) become something else (like a stick) when the item wears out fully?
- etc.

Your best bet is probably to write down exactly what you want feature-wise. It may be useful to get very familiar with an existing game so you have an actual example of each feature in action.

Once you have decided a baseline design, fully work through two or three different inventory tutorials on Youtube, perhaps even for the game example you have chosen above.

Or... do like I like to do: just jump in and make it up as you go. It is SOFT-ware after all... evolve it as you go!

Breaking down a large problem such as inventory:

https://forum.unity.com/threads/weapon-inventory-and-how-to-script-weapons.1046236/#post-6769558

All that said, if you wish to persist, you need to SERIOUSLY STEP UP your studying game. Here is how:

Tutorials and example code are great, but keep this in mind to maximize your success and minimize your frustration:

How to do tutorials properly, two (2) simple steps to success:

Step 1. Follow the tutorial and do every single step of the tutorial 100% precisely the way it is shown. Even the slightest deviation (even a single character!) generally ends in disaster. That's how software engineering works. Every step must be taken, every single letter must be spelled, capitalized, punctuated and spaced (or not spaced) properly, literally NOTHING can be omitted or skipped.

Fortunately this is the easiest part to get right: Be a robot. Don't make any mistakes.
BE PERFECT IN EVERYTHING YOU DO HERE!!

If you get any errors, learn how to read the error code and fix your error. Google is your friend here. Do NOT continue until you fix your error. Your error will probably be somewhere near the parenthesis numbers (line and character position) in the file. It is almost CERTAINLY your typo causing the error, so look again and fix it.

Step 2. Go back and work through every part of the tutorial again, and this time explain it to your doggie. See how I am doing that in my avatar picture? If you have no dog, explain it to your house plant. If you are unable to explain any part of it, STOP. DO NOT PROCEED. Now go learn how that part works. Read the documentation on the functions involved. Go back to the tutorial and try to figure out WHY they did that. This is the part that takes a LOT of time when you are new. It might take days or weeks to work through a single 5-minute tutorial. Stick with it. You will learn.

Step 2 is the part everybody seems to miss. Without Step 2 you are simply a code-typing monkey and outside of the specific tutorial you did, you will be completely lost. If you want to learn, you MUST do Step 2.

Of course, all this presupposes no errors in the tutorial. For certain tutorial makers (like Unity, Brackeys, Imphenzia, Sebastian Lague) this is usually the case. For some other less-well-known content creators, this is less true. Read the comments on the video: did anyone have issues like you did? If there's an error, you will NEVER be the first guy to find it.

Beyond that, Step 3, 4, 5 and 6 become easy because you already understand!

Finally, when you have errors... do not post here... go FIX YOUR ERROR.

Remember: NOBODY here memorizes error codes. That's not a thing. The error code is absolutely the least useful part of the error. It serves no purpose at all. Forget the error code. Put it out of your mind.

The complete error message contains everything you need to know to fix the error yourself.

The important parts of the error message are:

- the description of the error itself (google this; you are NEVER the first one!)
- the file it occurred in (critical!)
- the line number and character position (the two numbers in parentheses)
- also possibly useful is the stack trace (all the lines of text in the lower console window)

Always start with the FIRST error in the console window, as sometimes that error causes or compounds some or all of the subsequent errors. Often the error will be immediately prior to the indicated line, so make sure to check there as well.

All of that information is in the actual error message and you must pay attention to it. Learn how to identify it instantly so you don't have to stop your progress and fiddle around with the forum.