Health script and DestroyWhenDead

DestroyWhenDead.cs

using UnityEngine;
using System.Collections;

[RequireComponent(typeof(HasHealth))]
public class DestroyWhenDead : MonoBehaviour
{
	HasHealth health;
	///Lazy getter is safe here, because we used RequireComponent
	public HasHealth Health {
		get {
			if (health == null)
				health = GetComponent<HasHealth>();
			return health;
		}
	}

	void Awake()
	{
		//AddListener takes in a UnityAction, which can accept any function that matches it's interface
		Health.OnDeath.AddListener(DestroyObject);

		//inline delegates are also accepted
		//Health.OnDeath.AddListener(delegate () { Destroy(gameObject); });
	}

	void DestroyObject()
	{
		Destroy(gameObject);
	}
}

HasHealth.cs

using UnityEngine;
using UnityEngine.Events;

public class HasHealth : MonoBehaviour
{
	[SerializeField]
	float maxHealth = 100f;
	public float MaxHealth {
		get { return maxHealth; }
		set { maxHealth = value; }
	}

	protected float currentHealth;

	public virtual float Health{
		get{ return currentHealth; }
		set{
			bool wasAlive = IsAlive;
			currentHealth = Mathf.Clamp(value, 0f, MaxHealth);
			OnHealthChanged.Invoke();
			if (wasAlive && !IsAlive)
				OnDeath.Invoke();
			else if (!wasAlive && IsAlive)
				OnAlive.Invoke();
		}
	}

	/// <summary>
	/// returns a percent float between 0f and 1f
	/// </summary>
	public float HealthPercent { get { return Health / MaxHealth; } }

	///Called whenever this has health returns to life (called once in Awake)
	[SerializeField]
	UnityEvent onAlive;
	public UnityEvent OnAlive { get { return onAlive; } }

	///Called whenever the health is updated
	[SerializeField]
	UnityEvent onHealthChanged;
	public UnityEvent OnHealthChanged { get { return onHealthChanged; } }

	///Called whenever the health is updated and the object is now dead
	[SerializeField]
	UnityEvent onDeath;
	public UnityEvent OnDeath { get { return onDeath; } }

	public bool IsAlive{ get { return Health > 0; } }

	public virtual void Awake()
	{
		ResetHealth();
	}
	
	public virtual void TakeDamage(float damage)
	{
		Health -= damage;
	}

	public virtual void Heal(float amount)
	{
		Health += amount;
	}

	public void ResetHealth()
	{
		Health = maxHealth;
	}

	public void Kill()
	{
		TakeDamage(Health);
	}
}