Singleton Pattern

singleton_pattern.cs

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

public class GameManager : MonoBehaviour
{
  public static GameManager Instance { get { return _instance; } }
  private static GameManager _instance;

  void Awake()
  {
    //Check if instance already exists
    if (_instance == null)
    {
      //if not, set instance to this
      _instance = this;

      //If instance already exists and it's not this:
    }
    else if (_instance != this)
    {
      //Then destroy this. This enforces our singleton pattern, meaning there can only ever be one instance of a GameManager.
      Destroy(gameObject);
    }

    //Sets this to not be destroyed when reloading scene
    DontDestroyOnLoad(gameObject);
  }
}