Hai guys i need help why my scripts not running "i will make button next3dobject and prev3dobject"

using System.Collections;
using UnityEngine;
using UnityEngine.UI;

public class Tombolnextprev : MonoBehaviour {

public GameObject objek1,objek2,objek3;
public GameObject[] objek3D = new GameObject[3];
public int no = 1;

public void Start(){
	objek3D [0] = objek1;
	objek3D [1] = objek2;
	objek3D [2] = objek3;
}
public void nextObject(){
	if (no < 3){
		no++;
	}
}

public void prevObject(){
	if (no > 1){	
		no--;
	}
}

public void PindahObjeck(){
	if (gameObject = "Object"){
		nextObject ();
	}
	if (gameObject = "Object"){
		prevObject ();
	}
}

public void Update(){
	if (no == 1) {
		objek1.SetActive(true);
		objek2.SetActive(false);
		objek3.SetActive(false);
	}
	if (no == 2) {
		objek1.SetActive(false);
		objek2.SetActive(true);
		objek3.SetActive(false);
	}
	if (no == 3) {
		objek1.SetActive(false);
		objek2.SetActive(false);
		objek3.SetActive(true);
	}
}

}

Hi, you could use a property to swap objects instead of doing it in Update.

Here, some code with comments :

public class ObjectListManager : MonoBehaviour
{
    [SerializeField] List<GameObject> objectList; // use SerializeField attribute to display/save in the editor, while not accessible from other classes

    private int _current = 0;
    private int Current
    {
        get {return _current;}
        set
        {
            if (value != _current) // if value is different
            {
                if (value >= 0 && value < objectList.Count); // if value is within List
                {
                    objectList[_current].SetActive (false); // disable previous
                    _current = value;
                    objectList[_current].SetActive (true); // enable new
                }
            }
        }
    }

    void Awake ()
    {
        // Disable all but first object
        for (int i = 1 ; i < objectList.Count ; i++)
            objectList*.SetActive (false);*

}
public void Next ()
{
// cycle when Current reaches objectList.Count-1
Current = Current < (objectList.Count -1) ? Current+1 : 0;
}
public void Previous ()
{
// cycle when Current reaches 0
Current = Current > 0 ? Current-1 : objectList.Count-1;
}
}