why my scale goes to zero on adding the script?

Unity Engine
,
1 
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;

public class adjustscale : MonoBehaviour
{
    public float rotationMin = 0.0f;
    public float rotationMax = 45.0f;
    public Slider scale;
    public Slider rotate;

    [SerializeField] float currentRotation = 0f;
    [SerializeField] float currentScale = 0f;

   
   // Start is called before the first frame update
    void Start()
    {
        rotate = GameObject.Find("rotate").GetComponent<Slider>();
        scale = GameObject.Find("scale").GetComponent<Slider>();


       
    }

    // Update is called once per frame
    void Update()
    {
        transform.localEulerAngles = new Vector3(0.0f, rotate.value, 0.0f);
        transform.localScale = new Vector3(scale.value, scale.value, scale.value);
       
    }

    private void OnGUI()
    {
        currentRotation = GUI.HorizontalSlider(new Rect(-280.0f, 165.0f, 228.0f, 57.0f), currentRotation, 0.0f, 45.0f);
        transform.localEulerAngles = new Vector3(0.0f, currentRotation, 0.0f);
        currentScale = GUI.HorizontalSlider(new Rect(-280.0f, 120.0f, 228.0f, 57.0f), currentScale, 0.0f, 2.0f);
        transform.localScale = new Vector3(currentScale, currentScale, currentScale);

       
   }
    public void AdjustAngle(float newAngle)
    { }
    public void AdjustScale(float newScale)
    { }
}
2

Your script has:
[SerializeField] float currentScale = 0f;

So unless you change the value in the inspector, currentScale = 0;

Then in the last line of the OnGUI() method you set the scale to currentScale, which is 0 unless you have set it to something else in the inspector.

As you can see from Unity - Manual: Order of execution for event functions onGUI takes place after Update and LateUpdate.

HTH
Al

3

thanks @AITheSlacker
can you answer my next question?