Unity - SetActive not defined

Question

When using a script to hide and unhide specific sprites on the click of a button, I get these two errors. Assets\Scripts\ButtonLeft.cs(26,5): error CS1061: 'int' does not contain a definition for 'SetActive' and no accessible extension method 'SetActive' accepting a first argument of type 'int' could be found (are you missing a using directive or an assembly reference?)

Assets\Scripts\ButtonLeft.cs(22,8): error CS1061: 'int' does not contain a definition for 'activeSelf' and no accessible extension method 'activeSelf' accepting a first argument of type 'int' could be found (are you missing a using directive or an assembly reference?)

I was assured by previous posts, some only dating back a few weeks, that activeSelf was the correct way to check whether a sprite was already hidden, and I have used SetActive before in this project with no issues. Here's the script I'm trying to run:

using System.Collections.Generic;
using UnityEngine;

public class ButtonLeft : MonoBehaviour
{

    public void Click ()
    {
    if (23.activeSelf)
    {
        23.SetActive (false);
        3.SetActive (true);
        1.SetActive (false);
    }
    if (3.activeSelf)
    {
        23.SetActive (false);
        3.SetActive (false);
        1.SetActive (true);
    }
    if (1.activeSelf)
    {
        23.SetActive (true);
        3.SetActive (false);
        1.SetActive (false);
    }
    }

    // Update is called once per frame
    void Update()
    {
        
    }
}

Is the syntax wrong in any way? Is activeSelf not the correct way to check whether an object is active or not?

Using Unity 2019.4.5f1 Personal

Answer 1

The reason you're getting those error messages is due to running them on integers instead of sprites. You need to use an instance of a GameObject.

You can acquire a reference to something of that sort in several ways. One would be by making a field that's exposed to the inspector and providing the reference through there.

using UnityEngine;

public class ButtonLeft : MonoBehaviour
{
    [SerializeField]
    private SpriteRenderer sprite1 = null;

    [SerializeField]
    private SpriteRenderer sprite3 = null;

    [SerializeField]
    private SpriteRenderer sprite23 = null;

    public void Click()
    {
        if (sprite23.gameObject.activeSelf)
        {
            sprite23.gameObject.SetActive(false);
            sprite3.gameObject.SetActive(true);
            sprite1.gameObject.SetActive(false);
        }
        if (sprite3.gameObject.activeSelf)
        {
            sprite23.gameObject.SetActive(false);
            sprite3.gameObject.SetActive(false);
            sprite1.gameObject.SetActive(true);
        }
        if (sprite1.gameObject.activeSelf)
        {
            sprite23.gameObject.SetActive(true);
            sprite3.gameObject.SetActive(false);
            sprite1.gameObject.SetActive(false);
        }
    }
}

How things may end up looking in the editor:

If you want to be able to drag in any game object as a reference

using UnityEngine;

public class ButtonLeft : MonoBehaviour
{
    [SerializeField]
    private GameObject sprite1 = null;

    [SerializeField]
    private GameObject sprite3 = null;

    [SerializeField]
    private GameObject sprite23 = null;

    public void Click()
    {
        if (sprite23.activeSelf)
        {
            sprite23.SetActive(false);
            sprite3.SetActive(true);
            sprite1.SetActive(false);
        }
        if (sprite3.activeSelf)
        {
            sprite23.SetActive(false);
            sprite3.SetActive(false);
            sprite1.SetActive(true);
        }
        if (sprite1.activeSelf)
        {
            sprite23.SetActive(true);
            sprite3.SetActive(false);
            sprite1.SetActive(false);
        }
    }
}