Script Error (EnemyHeal): Update() can not take parameters.

Questions & Answers
1

Here is a script

#pragma strict
var enemyHeal : int = -5;
var item : Transform;
var enemy : Transform;

function Update(col : Collider) {
	if(col.gameObject.tag == "Bullet")
	{
		enemyHeal -= 30;
	}
	if(enemyHeal <= 0)
	{
		var position : Vector3 = Vector3(Random.Range(-10.0, 10.0), 0, Random.Range(-10.0, 10.0));
		Instantiate(item, enemy.transform.position + Vector3(0,20,0) + position, Quaternion.identity);
		Destroy(this.gameObject, 2);
	}
}

When “Bullet” hits “Enemy” i got this error “Script Error (EnemyHeal): Update() can not take parameters.”

2

And the error is true. Update method does not take any parameter. What you are looking for is the OnTriggerEnter method to which you pass a Collider as argument.

So your code becomes:

#pragma strict
var enemyHeal : int = -5;
var item : Transform;
var enemy : Transform;

function OnTriggerEnter(col : Collider) {
    if(col.gameObject.tag == "Bullet")
    {
        enemyHeal -= 30;
    }
    if(enemyHeal <= 0)
    {
        var position : Vector3 = Vector3(Random.Range(-10.0, 10.0), 0, Random.Range(-10.0, 10.0));
        Instantiate(item, enemy.transform.position + Vector3(0,20,0) + position, Quaternion.identity);
        Destroy(this.gameObject, 2);
    }
}