Unity objects move automatically

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

public class move : MonoBehaviour
{
    public float speed = 2; //[1] 物体移动速度
    public Transform[] target;  // [2] 目标
    public float delta = 0.2f; // 误差值
    private static int i = 0;

    void Update()
    {
        moveTo();
    }

    void moveTo()
    {
        // [3] 重新初始化目标点
        target[i].position = new Vector3(target[i].position.x, transform.position.y, target[i].position.z);

        // [4] 让物体朝向目标点 
        transform.LookAt(target[i]);

        // [5] 物体向前移动
        transform.Translate(Vector3.forward * Time.deltaTime * speed);

        // [6] 判断物体是否到达目标点
        if (transform.position.x > target[i].position.x - delta
            && transform.position.x < target[i].position.x + delta
            && transform.position.z > target[i].position.z - delta
            && transform.position.z < target[i].position.z + delta)
            i = (i + 1) % target.Length;
    }
}