sending information to a function in another script to use

So I have an inventory system set up in a game I’m building. I’m still a beginner and I’ve been using tutorials to help me build it. Though, the tutorial left me with questions I can’t figure out how to solve on my own.

In my inventory script, I have a function that will give the player an item. It’s a public void called “GiveItem()”. In the bracket will be the item I wish to give the player.

It looks like this

public void GiveItem(int id)
    {
        Item itemToAdd = itemDatabase.GetItem(id);   //Gab the id number from the separate Item data base script I have built
        characterItems.Add(itemToAdd);  //Add that id to the inventory
        inventoryUI.AddNewItem(itemToAdd);
    }

I need it so that when the player interacts with a specific object, the player will be given a specific object. I could put every interaction I need in the inventory script, knowing I’d work, but it’d be messy and difficult. So I want to create a separate script with the requirements. Like, if the player clicks on this box, then, give them the item. But I can’t figure out how I’d be able to use the function in a different script.

I was hoping someone would have a solution.

Referencing different scripts is actually quite easy - but can get confusing if you don’t have a proper hierarchy and setup. Below I will discus methods and strategies to reference other scripts.

Method 1: Scripts on the Same Object

This is the easiest on to do. If you have to scripts on the same Transform/Object you can reference it with GetComponent<>(). For example you have two scripts on an object, InventoryItemsDatabase and InventoryControll.
You want to access InventoryItemsDatabase from the InventoryControll script. It will look like this

	public class InventoryControll : MonoBehaviour {

		// Variable to store script so we 
		// don't have to use GetComponent every time.
		InventoryItemsDatabase itemDB;
		
		// Assign in on Start
		void Start () {
			
			itemDB = GetComponent<InventoryItemsDatabase>();
		}
		
		// Usage Example
		void RemoveItem (int id){		
			itemDB.Remove(id);
		}
	}

Method 2: Referencing Objects from Parent Or Root

Say you have an hierarchy structure of objects

-> GameManager {Root Object}
	--> PlayerManager
	--> AIManager
	--> InventoryManager [InventoryManager, InventoryDatabase] {Parent Object to InventoryControll}		
		---> InventoryControll [InventoryControll]

Here we have the InventoryControll on a separate object that is a child if the InventoryManager object which contains two scripts, InventoryManager and InventoryDatabase.
If we want to access the InventoryDatabase we can use the following code:

// Assign in on Start
void Start () {
	// Using GetComponent
	itemDB = transform.parent.GetComponent<InventoryItemsDatabase>();
	
	// Using GetComponentInParent
	itemDB = GetComponentInParent<InventoryItemsDatabase>();
}

Similar if the object was in the root (The most top parent you can get) you can use the code:

transform.root.GetComponent<InventoryItemsDatabase>()

Method 3: Drop and Drag for non hierarchy structures

Another way to do it is to add a reference to the object, drop and drag that object onto a variable. Create a public variable as a Transform.

public Transform InventoryDatabaseTransform;

This variable will now be visible in the inspector. Simply while you have the InventoryControll object select in the hierarchy (so we can see the above variable in the inspector), click and drag the InventoryDatabase object from the inspector to the variable in the inspector.
You should now be able to use getcomponent in the InventoryControll script as such:

void Start () {
	itemDB = InventoryDatabaseTransform.GetComponent<InventoryDatabase> ();
}

Hope this helped. Just comment if you have further issues.

Method 4: SearchObject

Simply search for the object you want by name:

void Start () {
    itemDB = GameObject.Find("InventoryDatabase").GetComponent<InventoryDatabase>();
}

I hope this helped you out!

One way would be to create a script, give it to each box and assign them an id. Upon clicking the box, retrieve that id and call GiveItem passing in the id you retrieved.