how to use scroll view unity code example

Example: unity get scroll

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

// Input.mouseScrollDelta example
//
// Create a sphere moved by a mouse scrollwheel or two-finger
// slide on a Mac trackpad.

public class ExampleClass : MonoBehaviour
{
    private Transform sphere;
    private float scale;

    void Awake()
    {
        GameObject go = GameObject.CreatePrimitive(PrimitiveType.Sphere);
        sphere = go.transform;

        // create a yellow quad
        go = GameObject.CreatePrimitive(PrimitiveType.Quad);
        go.transform.Rotate(new Vector3(90.0f, 0.0f, 0.0f));
        go.transform.localScale = new Vector3(4.0f, 4.0f, 4.0f);
        go.GetComponent<Renderer>().material.color = new Color(0.75f, 0.75f, 0.0f, 0.5f);

        // change the camera color and position
        Camera.main.clearFlags = CameraClearFlags.SolidColor;
        Camera.main.transform.position = new Vector3(2, 1, 5);
        Camera.main.transform.Rotate(0, -160, 0);

        scale = 0.1f;
    }

    void OnGUI()
    {
        Vector3 pos = sphere.position;
        pos.y += Input.mouseScrollDelta.y * scale;
        sphere.position = pos;
    }
}