Do not know why using "this" for checking-CodePudding

I create an array called Zombies which includes all the Game Object in the scene. And I also create the foreach loop to check if the Zombies have attached ZombieState.cs. I'm following the book but it's not explaining clearly why we need zState==this.

using UnityEngine;

public class ZombieState : MonoBehaviour
{
    // Start is called before the first frame update
    void Start()
    {
        GameObject[] Zombies = (GameObject[])GameObject.FindObjectsOfType(typeof(GameObject));
        foreach (GameObject go in Zombies)
        {
            ZombieState zState = go.GetComponent<ZombieState>();
            if (zState == null || zState == this)
            {
                continue;
            }
        }

    }
}

CodePudding user response：

In general, the this keyword refers to the current instance of a class and is often used to distinguish between instance variables and local variables with the same name. In your case, this refers to the ZombieState component attached to the current GameObject, while zState refers to the ZombieState component being iterated over in the for-each loop.

zState == this is a comparison that checks if the ZombieState component of the current GameObject (referenced by the this keyword) is the same as the ZombieState component that is being iterated over in the for-each loop. That was obtained via GameObject[])GameObject.FindObjectsOfType(typeof(GameObject)).

If zState == this is true, it means that the current ZombieState component being iterated over is the same as the ZombieState component of the current GameObject. In this case, the code will skip over the current iteration of the for-each loop and move on to the next one.

CodePudding user response：

this is a C# statement that simply refers to “this” class.

In your example, if you read through the code, you’re asking Unity to list all of the instances of ZombieState. The class you’re calling this from IS also a ZombieState. So in essence the code is asking for ALL the instances of ZombieState, and when it comes time to do something with all of the instances, the foreach statement, we want to do it to all the other instances.