SchoolFightingSimple/Assets/Scripts/AppManager.cs

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

public class AppManager : MonoBehaviour
{
    public static void LoadScene(int index)
    {
        UnityEngine.SceneManagement.SceneManager.LoadScene(index);
    }

    public List<GameObject> UI_Groups = new List<GameObject>();
    public void ShowAndHide(int showIndex) 
    {
        Assert.IsTrue(showIndex < UI_Groups.Count);

        foreach (GameObject group in UI_Groups)
        {
            group.SetActive(false);
        }

        UI_Groups[showIndex].SetActive(true);
    }

    public void QuitApp()
    {
        Application.Quit();
    }
}