Get mouse input in Unity

To get the mouse input event in Unity, we have to create a script attached to your game object. Then add the following script to it:

Mouse click

using UnityEngine;
using System.Collections;

// Detects clicks from the mouse and prints a message
// depending on the click detected.

public class ExampleClass : MonoBehaviour
{
    void Update()
    {
        if (Input.GetMouseButtonDown(0))
            Debug.Log("Pressed left button.");

        if (Input.GetMouseButtonDown(1))
            Debug.Log("Pressed right button.");

        if (Input.GetMouseButtonDown(2))
            Debug.Log("Pressed middle click.");
    }
} 

Mouse scroll

void Update()
{
    Debug.Log("mouse: " + Input.mouseScrollDelta.y );
}

If you scroll you mouse up and down, you will get the log like:

mouse: 6.643539
mouse: 12.98123