Melee KnockBack using addforce

when I tried to use add force it will give me this error
NullReferenceException: Object reference not set to an instance of an object
Help will be appreciative

Code (CSharp):

1. public class enemyScript : MonoBehaviour {
2.     public int currHealth;
3.     public int maxHealth=30;
4.     private Rigidbody2D enemeyRigidBody;
5.     // Use this for initialization
6.     void Start () {
7.         currHealth = maxHealth;
8.         Debug.Log(currHealth);
9.     }
10.  
11.     // Update is called once per frame
12.     void Update ()
13.     {
14.  
15.         if (currHealth <= 0)
16.         {
17.  
18.             Destroy(gameObject);
19.         }
20.          
21.    }
22.    
23.  
24.     public void underAttack(int damage)
25.     {
26.         currHealth -= damage;
27.         Debug.Log(currHealth);
28.          
29.     }
30.     void OnTriggerEnter2D(Collider2D col)
31.     {
32.         if (col.CompareTag("jabbing"))
33.         {
34.  
35.             enemeyRigidBody.AddForce(Vector3.left * 10);
36.         }
37.     }
38.    
39. }
40.  

 

I can't see that you actually set enemeyRigidBody anywhere in your code, which means that it is set to null. You need to assign it a value somewhere before the OnTriggerEnter2D event.

 

oh crap thanks another question
I got the code to work but I have another issue and it's with send message upward being called twice
attack trigger

Code (CSharp):

1. using UnityEngine;
2. using System.Collections;
3.  
4. public class jabTrigger : MonoBehaviour {
5.     public static int jabDamage = 2;
6.     public GameObject animationObject;
7.     GameObject col;
8.     void Start()
9.     {
10.  
11.          }
12.     void OnTriggerEnter2D(Collider2D col)
13.     {
14.         if (col.isTrigger != true && col.CompareTag("enemy"))
15.         {
16.          
17.             col.SendMessageUpwards("underAttack", jabDamage);
18.         }
19.  
20.     }
21.  
22. }

Code (CSharp):

1. using UnityEngine;
2. using System.Collections;
3.  
4. public class enemyScript : MonoBehaviour {
5.     private bool knock = false;
6.     private float knockbackDuration = .3f;
7.     private float knockbackTimer = 0;
8.     public int currHealth;
9.     public int maxHealth=30;
10.     private Rigidbody2D enemeyRigidBody;
11.  
12.     // Use this for initialization
13.     void Start () {
14.         enemeyRigidBody = GetComponent<Rigidbody2D>();
15.         enemeyRigidBody.isKinematic = true;
16.         currHealth = maxHealth;
17.         Debug.Log(currHealth);
18.      
19.     }
20.  
21.     // Update is called once per frame
22.     void Update ()
23.     {
24.         if (knock)
25.         {
26.             if (knockbackTimer > 0)
27.             {
28.                 knockbackTimer -= Time.deltaTime;
29.             }
30.             else
31.             {
32.                 knock = false;
33.                 enemeyRigidBody.isKinematic = true;
34.             }
35.         }
36.         if (currHealth <= 0)
37.         {
38.  
39.             Destroy(gameObject);
40.         }
41.    
42.     }
43.  
44.  
45.     public void underAttack(int damage)
46.     {
47.      
48.         currHealth -= damage;
49.         Debug.Log(currHealth);
50.          
51.     }
52.     void OnTriggerEnter2D(Collider2D col)
53.     {
54.         if (col.CompareTag("jabbing"))
55.         {
56.             knock = true;
57.             knockbackTimer = knockbackDuration;
58.             enemeyRigidBody.isKinematic = false;
59.             enemeyRigidBody.AddForce(Vector3.right * 100);
60.         }
61.      
62.      
63.     }
64.  
65. }
66.  

 

try add in Line 9:
enemeyRigidBody = GetComponent <Rigidbody2D> ();