Attacking more than one enemy with same tag, but unity only allows one enemy at a time?

Questions & Answers
1

Hi, this problem has been stressing me all night and any help is appreciated.
I am using c#.
I have two types of enemies, enemy1 and enemy2.

I created an enemy code and an attack code. basically it works fine for one on one situation. But if i say, use ctrl-d and make more of the same enemy, problems occur.

Firstly , i can fight many, but as soon as one dies, I cannot kill the other. (‘missing game object’ shows up). I target those with enemy1 and enemy2 tag. If either enemy dies, I cannot kill the other.

Secondly if I add many enemies, with same tags. So in this example, i spawn 3 guys, all with enemy1 tag. It seems i cannot kill them in any order I want.

I understand my problem is similar to:

http://answers.unity3d.com/questions/328022/i-need-help-to-attack-various-enemies-with-the-sam.html

but I wasnt unable to convert the javascript to c#.

From my understanding, my code only allows me to select two enemies to fight. If i make them chose from tags, they will randomly chose enemies with my selected tag.(So if i spawn 3 guys with enemy1 tags, unity chooses one of them at random to be my opponent and the other two are untouchable)

I do believe my code would need perhaps some array style fix but I am absolutely lose. Below is the attack code.

using UnityEngine;
using System.Collections;

public class atkm1 : MonoBehaviour {
	public GameObject target;
	public GameObject target1;
	public float attackTimer;
	public float coolDown;


	// Use this for initialization
	void Start () {
		attackTimer = 0;
		coolDown =0.0f;

	}
	
	// Update is called once per frame
	
	void Update () {
		
		GameObject go = GameObject.FindGameObjectWithTag("enemy1");
		target = go;
		
		GameObject go1 = GameObject.FindGameObjectWithTag("enemy2");
		target = go1;
		
		
		if(attackTimer > 0)
			attackTimer -= Time.deltaTime;
		if(attackTimer < 0)
			attackTimer = 0;
		if(Input.GetKeyUp(KeyCode.F)) {
		if(attackTimer == 0) {
		Attack();
		attackTimer = coolDown;
			}
		}	
	}
	
	private void Attack() {

		float distance = Vector3.Distance(target.transform.position, transform.position);
		float distance1 = Vector3.Distance(target1.transform.position, transform.position);
		
		//calculate damage for enemy1 tag 
		if(distance < 2.5f) {
				hpP eh = (hpP)target.GetComponent("hpP");
				eh.AddjustCurrentHealth(-10);
		}
			
		//calculate damage for enemy2 tag			
		if(distance1 < 2.5f) {
				hpL eh = (hpL)target1.GetComponent("hpL");
				eh.AddjustCurrentHealth(-10);
		}	
		}
	}

One last thing, I use public so i can ‘drag and drop’ the enemy objects in for testing purposes. Ofcourse even if i do that, i get the same failed results. Basically, the moment i kill one off, then i get the missing gameobject error and my player is unable to attack.
EG. target:enemy1
target1:enemy2

if i kill enemy1,

target:missing object
target1:enemy2

any help is muchly appreciated. Basically I have a prefab for an enemy that works and attack scripts that works. I wish to fight more than one enemy with same tag in any order .

2

Edit: I forgot that you want to attack multiple targets. For that you will need to make the target variable a generic list (means a dynamic array) and then check every target in the array inside the Attack Function:

using UnityEngine;
using System.Collections;
using System.Collections.Generic;

public class atkm1 : MonoBehaviour {
    public List<GameObject> targets;
    public float attackTimer;
    public float coolDown;


    // Use this for initialization
    void Start () {
       target = new List<GameObject>();
       attackTimer = 0;
       coolDown =0.0f;

    }

    // Update is called once per frame

    void Update () {

       GameObject go = GameObject.FindGameObjectWithTag("enemy1");
       GameObject go1 = GameObject.FindGameObjectWithTag("enemy2");

       if(go != null)
          targets.Add(go);

       if(go1 != null)
          targets.Add(go1);

       if(attackTimer > 0)
           attackTimer -= Time.deltaTime;
       if(attackTimer < 0)
           attackTimer = 0;
       if(Input.GetKeyUp(KeyCode.F)) {
           if(attackTimer == 0) {
               Attack();
               attackTimer = coolDown;
           }
       } 
    }

    private void Attack() {

       foreach(GameObject target in targets)
       {
       
          float distance = Vector3.Distance(target.transform.position, transform.position);
          float distance1 = Vector3.Distance(target1.transform.position, transform.position);

          //calculate damage for enemy1 tag 
          if(distance < 2.5f) {
             hpP eh = (hpP)target.GetComponent("hpP");
             eh.AddjustCurrentHealth(-10);
          }

          //calculate damage for enemy2 tag        
          if(distance1 < 2.5f) {
             hpL eh = (hpL)target1.GetComponent("hpL");
             eh.AddjustCurrentHealth(-10);
          }

       }

    }
}

GameObject.FindGameObjectWithTag() method will not always return a GameObject because sometimes there are no objects found with the given tag. You need to make sure it’s not null before assigning it.

   GameObject go = GameObject.FindGameObjectWithTag("enemy1");

   // Assign go to target only if it's not null
   if(go != null)
      target = go;

   GameObject go1 = GameObject.FindGameObjectWithTag("enemy2");

   // Assign go1 to target only if it's not null
   if(go1 != null)
      target = go1;

Also, in your Attack() function you need to check if target is not null before doing anything:

private void Attack() {

   // If target is null then all the code will not be executed
   if(target == null)
     return;

   float distance = Vector3.Distance(target.transform.position, transform.position);
   float distance1 = Vector3.Distance(target1.transform.position, transform.position);

   //calculate damage for enemy1 tag 
   if(distance < 2.5f) {
       hpP eh = (hpP)target.GetComponent("hpP");
       eh.AddjustCurrentHealth(-10);
   }

   //calculate damage for enemy2 tag        
   if(distance1 < 2.5f) {
       hpL eh = (hpL)target1.GetComponent("hpL");
       eh.AddjustCurrentHealth(-10);
   } 
}
3

Instead of a single GameObject per enemy, I replaced it with a List. You can still drag-and-drop enemies into the component like before for testing. Code not tested, but it shows Lists and arrays a bit.

using UnityEngine;
using System.Collections;
using System.Collections.Generic;

public class atkm1 : MonoBehaviour {
	public List<GameObject> targets;
    public float attackTimer;
    public float coolDown;

    // Use this for initialization
    void Start () {
       attackTimer = 0;
       coolDown =0.0f;
		
		GameObject[] enemyTargets = GameObject.FindGameObjectsWithTag("enemy1");
		if (enemyTargets != null)
		{
			foreach(GameObject go in enemyTargets)
			{
				targets.Add(go);
			}
		}
		
		GameObject[] moreTargets = GameObject.FindGameObjectsWithTag("enemy2");
		if (moreTargets != null)
		{
			foreach(GameObject go in moreTargets)
			{
				targets.Add(go);
			}
		}	
		
    }

    // Update is called once per frame
    void Update () {
				
       	if(attackTimer > 0)
        	attackTimer -= Time.deltaTime;
		
       	if(attackTimer < 0)
        	attackTimer = 0;
		
      	if(Input.GetKeyUp(KeyCode.F)) {
	       	if(attackTimer == 0) {
    	   		Attack();
       			attackTimer = coolDown;
         	}
       	}
		
    }
	private void Attack()
	{
		float distance = float.MaxValue;
		if (targets == null) return;
		
		foreach (GameObject target in targets)
		{
			if (target != null)
			{
				distance = Vector3.Distance(target.transform.position, transform.position);
			
				if (distance < 2.5f) 
				{
					hpP eh = (hpP)target.GetComponent("hpP");
					if (eh != null)
					{
        				eh.AddjustCurrentHealth(-10);
					}
					
					hpL eh2 = (hpL)target.GetComponent("hpL");
					if (eh2 != null)
					{
        				eh2.AddjustCurrentHealth(-10);
					}
				}
			}
		}
	}
	
}