LAZY INSTANTIATION

OBJECTIVE: Create a GameManager Script to allow for Lazy Instantiation if the instance of the GameManager returns NULL

public class GameManager: MonoBehaviour
{
    private static GameManager _instance;
    public static GameManager Instance
    {
        get
        {
            if(_instance == null)
            {
                GameObject go = new GameObject("GameManager");
                go.AddComponent<GameManager>();
            }
            
            return _instance;
        }
    }
    
    private void Awake()
    {
        _instance = this;
    }
}

CODE BREAKDOWN

• LINE 3 --> Creates a private static instance of the current class

  • _instance is going to define the instance of THIS GameManager and there never can be more than ONE instance of a single class

• LINE 4 --> Creates a public static instance of this class

  • Needed for script communication

  • Needs to be a property that other classes GET but cannot SET

• LINE 6-15 --> Defines the GET property for the Instance property

  • when another script calls upon the Instance property the following happens...

    • FIRST: program checks that _instance is not NULL (I.E. that the class exists within the hierarchy)

    • SECOND: If _instance is null, a new game object is created within the hierarchy and the GameManager script is attached.

      • ==> LAZY INSTANTIATION <==

    • THIRD: If not NULL the property returns the instance of itself, allowing the other script access

• LINE 18-21 --> Initialized the singleton while the program initially loads

  • This is where the program assigns _instance to this script