Array & Vector3 in C#

I want the covert javascript to C#

private var posStoreX : Array = [];
private var posStoreZ : Array = [];

function OnTouchBegin(pointCurrent : Vector3) 
{
  posStoreX.Clear();  //empties the array
  posStoreZ.Clear();  //empties the array
}

function AddSplinePoint(pointStore : Vector3) 
{
  posStoreX[countDrag] = pointStore.x;
  posStoreZ[countDrag] = pointStore.z;
  countDrag ++;// next position
}

function FixedUpdate() 
{
  targetWaypoint = Vector3(posStoreX[countMove], 0 ,posStoreZ[countMove]);
}

When I covert the C# , have a lot of error , how to covert? thanks!!

I would do it like this:

// C#
using System.Collections.Generic;

public class MyClass : MonoBehaviour
{
    public Vector3 targetWaypoint;
    public int countMove = 0;
    private var posStore = new List<Vector3>();
    
    public void OnTouchBegin()
    {
        countMove = 0;
        posStore.Clear();  //empties the array
    }
    
    public void AddSplinePoint(Vector3 pointStore) 
    {
        pointStore.y = 0.0f;
        posStore.Add(pointStore);
    }
    
    void Update() // It makes no sense to set the waypoint in Fixedupdate
    {
        if (countMove >= 0 && countMove < posStore.Count)
            targetWaypoint = posStore[countMove];
    }
}

You should use targetWaypoint = new Vector3(); instead of targetWaypoint = Vector3();