Help me with simple code plz

Hey, can someone help me with this simple code ? When I find a new item it is added to my list but "i" is always 0, so i cannot prevent adding same item to the list

Code (CSharp):

1.  
2.  
3. public List<Item> itemsInInventory = new List<Item>();
4.  
5.  
6.  
7.     public void AddResource(List<Item> items)
8.     {
9.         foreach(Item item in items)
10.         {
11.             if (itemsInInventory.Count == 0)
12.             {
13.                 itemsInInventory.Add(item);
14.             }
15.             for (int i = 0; i < itemsInInventory.Count; i++)
16.             {
17.                 if (itemsInInventory.name == item.name)
18.                 {
19.                     Debug.Log("same name");
20.                     return;
21.                 }
22.                 else
23.                 {
24.                     Debug.Log("find new item");
25.                     itemsInInventory.Add(item);
26.                 }
27.             }
28.         }
29.     }
30. }

 

itemsInInventory.name

does this even compile? I've never seen anything like this before.

Anyhow, the most simple way of doing it would be something like this:

Code (CSharp):

1. foreach (Item itemToAdd in items)
2. {
3.    foreach (Item ownedItem in itemsInInventory)
4.    {
5.       if (itemToAdd.name != ownedItem.name)
6.       {
7.          itemsInInventory.Add(itemToAdd);
8.       }
9.    }
10. }

The above is super ugly, but it's simple enough for you to understand without needing to explain a bunch of stuff you probably don't need to worry about now.

 

I think you just want to replace

return;

with

continue;

 

ou there was if

Code (CSharp):

1. (itemsInInventory[i].name == item.name)

i probably delete it before .. and I tried this code before what you reply me, but it's not adding item to the list idk why

 

Code (CSharp):

1. // breaks the loop
2. return;
3.  
4. // goes to next iteration { i }
5. continue;

when you use return, its telling the compiler the loop is finished. so it skips all other i*(n).

untested;

Code (CSharp):

1. List<GameObject> example = new List<GameObject>();
2.     public void AddToList(ref List<GameObject> new_list)
3.     {
4.         foreach (GameObject obj in new_list)
5.         {
6.             foreach (GameObject existing_obj in example)
7.                 if (obj.name == existing_obj.name)
8.                     continue;
9.  
10.             example.Add(obj);
11.  
12.         }
13.     }

 

when i replace return, than it's Adding much more items to the list

 

But I'm adding item after the logic, but If you see something wrong there, let me know I tried many things but none of it is working.

 

With this code, there is alarm when i collect second item:

InvalidOperationException: Collection was modified; enumeration operation may not execute.
System.ThrowHelper.ThrowInvalidOperationException (System.ExceptionResource resource) (at <695d1cc93cca45069c528c15c9fdd749>:0)

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4.  
5. public class Inventory : MonoBehaviour
6. {
7.  
8.     public List<Item> itemsInInventory = new List<Item>();
9.  
10.  
11.     public void AddResource(List<Item> items)
12.     {
13.         foreach (Item itemToAdd in items)
14.         {
15.             if (itemsInInventory.Count == 0)
16.             {
17.                 itemsInInventory.Add(itemToAdd);
18.             }
19.             foreach (Item inventoryItem in itemsInInventory)
20.             {
21.                 if (inventoryItem.name != itemToAdd.name)
22.                 {
23.                     itemsInInventory.Add(itemToAdd);
24.                 }
25.             }
26.         }
27.        
28.     }
29.  
30. }

 

It was written before I check new replies, sorry.

So If I understand what you mean, I write this code.. now alarm message is gone, but still second item is duplicating.

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4.  
5. public class Inventory : MonoBehaviour
6. {
7.     bool isFound = false;
8.  
9.     public List<Item> itemsInInventory = new List<Item>();
10.  
11.  
12.     public void AddResource(List<Item> items)
13.     {
14.         foreach (Item itemToAdd in items)
15.         {
16.             if (itemsInInventory.Count == 0)
17.             {
18.                 itemsInInventory.Add(itemToAdd);
19.             }
20.             foreach (Item inventoryItem in itemsInInventory)
21.             {
22.                 if (inventoryItem.name != itemToAdd.name)
23.                 {
24.                     isFound = true;
25.                 }
26.                
27.             }
28.             if (isFound)
29.             {
30.                 itemsInInventory.Add(itemToAdd);
31.                 isFound = false;
32.             }
33.  
34.         }
35.        
36.     }
37.  
38. }

 

I'm trying, but none of it is working o.o .. I was thinking about List.Exist.. how it works ?

 

Code (CSharp):

1.     bool isFound = false;
2.  
3.     public List<Item> itemsInInventory = new List<Item>();
4.  
5.  
6.     public void AddResource(List<Item> items)
7.     {
8.         foreach (Item itemToAdd in items)
9.         {
10.            
11.             if (itemsInInventory.Count == 0) //If I delete this statement, than it cannot add any item to the list
12.             {
13.                 itemsInInventory.Add(itemToAdd);
14.             }
15.             else
16.             {
17.                 foreach (Item inventoryItem in itemsInInventory)
18.                 {
19.                     Debug.Log(itemsInInventory.Count);
20.                     if (itemToAdd.name != inventoryItem.name)
21.                     {
22.                         isFound = true;
23.                     }
24.                     else
25.                     {
26.                         isFound = false;
27.                     }
28.                 }
29.                 if(isFound)
30.                 {
31.                     itemsInInventory.Add(itemToAdd);
32.                 }
33.             }
34.         }
35.        
36.        
37.     }

 

It's not working o.o

 

Before we go too much further down the hairy rathole of pair programming an inventory system over the forums, please keep this in mind and decide if you are prepared to tackle this level of problem today:

There is NOTHING simple about inventories.

These things (character customization, inventories, shop systems) are fairly tricky hairy beasts, definitely deep in advanced coding territory. They contain elements of:

- a database of items that you can possess / equip
- a database of the items you actually possess / equip
- 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
- 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?
- 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?
- can users substantially modify items with other things like spells, gems, etc.?
- does a worn-out item (shovel) become something else (like a stick) when the item wears out?
- 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

"Combining a bunch of stuff into one line always feels satisfying, but it's always a PITA to debug." - Star Manta on the Unity3D forums

 

Got it ... Jeez I'm dummy.. I can't search for indivitual item in inventory and than compare this individual item with itemToAdd .... and the code is so easy to understand

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4.  
5. public class Inventory : MonoBehaviour
6. {
7.     public bool isFound = false;
8.  
9.     public List<Item> itemsInInventory = new List<Item>();
10.  
11.  
12.     public void AddResource(List<Item> items)
13.     {
14.         foreach (Item itemToAdd in items)
15.         {
16.             if (itemsInInventory.Count == 0)
17.             {
18.                 itemsInInventory.Add(itemToAdd);
19.             }
20.             else
21.             {
22.                 if (!itemsInInventory.Contains(itemToAdd))
23.                 {
24.                     itemsInInventory.Add(itemToAdd);
25.                 }
26.                  
27.             }
28.         }
29.        
30.        
31.     }
32.  
33. }

 

It can be even simpler:

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4.  
5. public class Inventory : MonoBehaviour
6. {
7.     public bool isFound = false;
8.     public List<Item> itemsInInventory = new List<Item>();
9.  
10.     public void AddResource(List<Item> items)
11.     {
12.         foreach (Item itemToAdd in items)
13.         {
14.             if (!itemsInInventory.Contains(itemToAdd))
15.             {
16.                 itemsInInventory.Add(itemToAdd);
17.             }
18.         }
19.     }
20. }

I was just worried to suggest Contains because your previous code was comparing names, so I wasn't sure if

Item

was something that would play nicely with that.