Do I need to initialize a public List variable in Unity?

Question

I want to create a list of horses and print the name of the Horses that are stored in the list. Although I got the answer correct as I desired, there's one thing that is puzzling me when I declare a list variable.

I declared it as:

public List<string> myFavouriteHorses;

and in an example I have seen it's declared like this:

public List<string> myFavouriteHorses = new List<string> ();

Despite this difference, both of them worked. What's the difference between these two approaches? Does it matter which one I use?

Here's the entire code which i tried:

using UnityEngine; 
using System.Collections.Generic;

public class LearningScript : MonoBehaviour {

    public List<string> myFavouriteHorses = new List<string> ();

    void Start(){
        myHorses ();
        }

    void Update(){
        if (Input.GetKeyDown (KeyCode.Return)) {
            Print ();

        }

    }

    void myHorses(){

        myFavouriteHorses.Add ("Grey Horse");
        myFavouriteHorses.Add ("Black Horse");
        myFavouriteHorses.Add ("Rudolph Horse");
        myFavouriteHorses.Add ("Biting Horse");
    }

    void Print(){
        Debug.Log ("This list has " + myFavouriteHorses.Count + " horses");

        Debug.Log ("The horse at index 1 is " + myFavouriteHorses [1]);
        Debug.Log ("The horse at index 2 is " + myFavouriteHorses [2]);
        Debug.Log ("The horse at index 3 is" + myFavouriteHorses [3]);

    }

}

Here's the output

Why doesn't it make a difference whether or not I initialize the List with new before using it?

Answer 1

Unity's editor automatically creates the new List () part when generating the game. That's how you can already populate it with data in the editor. Things assigned in the editor will be added to the gameobject even BEFORE Awake() and Start() so if you assign the variable somewhere in Awake() or Start() (or in a function called during one of them, such as myHorses()) it will override the assignment done in the editor.