Input.GetMouseButton

Description

Returns whether the given mouse button is held down.

button values are 0 for left button, 1 for right button, 2 for the middle button.

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

function Update() {
    if(Input.GetMouseButton(0))
        Debug.Log("Pressed left click.");
    if(Input.GetMouseButton(1))
        Debug.Log("Pressed right click.");
    if(Input.GetMouseButton(2))
        Debug.Log("Pressed middle click.");
}

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour {
    void Update() {
        if (Input.GetMouseButton(0))
            Debug.Log("Pressed left click.");
        
        if (Input.GetMouseButton(1))
            Debug.Log("Pressed right click.");
        
        if (Input.GetMouseButton(2))
            Debug.Log("Pressed middle click.");
        
    }
}