foreach (var i in x)

foreach (var i in x)
    list.Append(i);

for (int i = 0; i < x.Length(); ++i)
    list.Append(x[i]);

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

public class GameField : MonoBehaviour
{
    public GameObject eField;
    GameObject[,] Field;
    public int lenField;

    void CreateField()
    {
        Vector3 StartPoze = transform.position;
        float XX = StartPoze.x;
        float YY = StartPoze.y;
        Field = new GameObject[lenField, lenField];

        for (int Y = 0; Y < lenField; Y++)
        {
            for (int X = 0; X < lenField; X++)
            {
                Field[X, Y] = Instantiate(eField);
                Field[X, Y].GetComponent<Chanks>().Index = 0;
                Field[X, Y].transform.position = new Vector3(XX, YY, StartPoze.z);

                XX++;
            }

            XX = StartPoze.x;
            YY--;
        }
    }

    void Start()
    {
        CreateField();
    }

    void Update() {}
}