Why does my function get called for every object?

Hi, I'm new to unity. I have a script called "PickUp" which I've attached to items that are able to be picked up. I've got it working, but I have a question.

The logic is basically:
onTriggerEnter() -> allow pickup
onTriggerExit() -> disallow pickup
update() -> if pickup is allowed and user is pressing E, call pickItem()
pickItem() -> For now, log the value of the objects

I've attached it here:

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4.  
5. public class PickUp : MonoBehaviour
6. {
7.  
8.     public int value;
9.  
10.     private bool inRange;
11.  
12.     private void Start()
13.     {
14.      }
15.  
16. // checks that the player is in range
17.     private void OnTriggerEnter2D(Collider2D other)
18.     {
19.         if (other.CompareTag("Player"))
20.         {
21.             inRange = true;
22.             Debug.Log("pickup allowed.");
23.  
24.         }
25.     }
26.  
27. // when the player is no longer in range, the object cannot be picked up
28.     private void OnTriggerExit2D(Collider2D other)
29.     {
30.         if (other.CompareTag("Player"))
31.         {
32.             inRange = false;
33.             Debug.Log("pickup no longer allowed.");
34.  
35.         }
36.     }
37.  
38.  
39.     private void PickItem()
40.     {
41.         Debug.Log("this item is valued at " + value);
42.  
43.     }
44.  
45.     private void Update()
46.     {
47.         if (inRange = true && Input.GetKeyDown(KeyCode.E))
48.         {
49.             PickItem();
50.         }
51.  
52.     }
53. }

At the moment, I have 4 items with the PickUp script.
However, when I go to an object and press E, I get the value of all 4 objects instead of the one my player is touching.



I also tried Debug.log(gameObject), but it ended up logging each one as well.


I finally got it to work by moving my logic to onTriggerStay( ).
But I still want to know if there's a proper way to call a function for a single gameobject.

 

This line. The = operator is assignment. The == operator is testing (boolean).

You are assigning (and implicitly testing) the value that evalutes from

true && keydown

in every instance.

You should use == but you should group them by parentheses.

Code (csharp):

1. if ((inRange == true) && Inputetc)

In fact, you don't even really need the

true

, you can just use the

(inRange && Inputetc)

expression for your if condition.

But keeping the true is not bad, it's actually a style preference for some, although I don't care for it much.

However, always keep the parens.

 

Your problem had nothing to do with OnTriggerEnter, but rather your Update check itself.

inRange = true is an assignment call. It means, set the value of inRange to true.

inRange == true or even just putting inRange means to compare the value to true.

Edit: @Kurt-Dekker beat me to it. lol.

 

@Kurt-Dekker @Brathnann gosh, thank you! I was losing my mind. Just tested it and it works! And dang yeah, since it is a boolean I could have done the check using the property name