Unity_C#EventExample

public class GameManager: MonoBehaviour
{
    public delegate void OnCompleted();
    public static event OnCompleted OnEndTurn;

    private void Update()
    {
        if (Input.GetButtonUp("Fire1"))
        {
            //Here I use the fire button to end the turn
            if (OnEndTurn != null)
            {
                //All the code you want to run before the turn ends goes here
                //.....
                OnEndTurn();
            }
        }
    }
}

//Now the listner
public class Listner: MonoBehaviour
{
    void Start()
    {
        //Subscribe to the event
        HelpOthers.OnEndTurn += WhatToDoWhenTurnEnds;
    }

    void WhatToDoWhenTurnEnds()
    {
        print("I do this when turn ends");
    }
}