Building a turret without shooting

Hi there, I'm trying to build a turret in a tower defence that kills the enemies but doesn't shoot, so it's a range tower. When I find the enemy then I want to destroy() but it doesn't let me do it.

Code (CSharp):

1. using UnityEngine;
2.  
3. using UnityEngine;
4.  
5. public class Firewall : MonoBehaviour
6. {
7.  
8.  
9.  
10.     [Header("Attributes")]
11.     public float range = 0.6f;
12.  
13.     [Header("Unity Setup")]
14.     public string enemyTag = "Enemy";
15.     public Transform target;
16.  
17.  
18.     void Start(){
19.       InvokeRepeating("UpdateTarget", 0f, 0.5f);
20.     }
21.  
22.     private void UpdateTarget()
23.     {
24.       GameObject[] enemies = GameObject.FindGameObjectsWithTag(enemyTag);
25.       float shortestDistance = Mathf.Infinity;
26.       GameObject nearestEnemy = null;
27.  
28.       foreach(GameObject enemy in enemies)
29.       {
30.         float distanceToEnemy = Vector2.Distance(transform.position, enemy.transform.position);
31.         if(distanceToEnemy < shortestDistance)
32.         {
33.           shortestDistance = distanceToEnemy;
34.           nearestEnemy = enemy;
35.        
36.         }
37.       }
38.  
39.       if(nearestEnemy != null && shortestDistance <= range)
40.       {
41.         target = nearestEnemy.transform;
42.       } else
43.       {
44.         target = null;
45.       }
46.  
47.     }
48.  
49.  
50.     public void Impact()
51.     {
52.       Debug.Log("Impact with virus");
53.       Destroy(target.gameObject);
54.     }
55.  
56.     void OnDrawGizmosSelected()
57.     {
58.       Gizmos.color = Color.red;
59.       Gizmos.DrawWireSphere(transform.position, range);
60.  
61.     }
62.  
63.   }
64.  
65.  

 

When is

Impact()

called? It looks like your logic for finding the nearest enemy is working fine, but I don't see when that nearest enemy is supposed to be destroyed.

 

Sorry I uploaded the wrong one, When I add impact() here, the it kills only the first one

Code (CSharp):

1. if(nearestEnemy != null && shortestDistance <= range)
2.       {
3.         target = nearestEnemy.transform;
4.         Impact();
5.       } else
6.       {
7.         target = null;
8.       }