Input.GetMouseButtonDown

Description

Returns true during the frame the user pressed the given mouse button.

Note: This API is part of the legacy Input class, and not recommended for new projects. The documentation is provided here to support legacy projects that use the old Input Manager and Input class. For new projects you should use the newer and Input System Package. (read more).

Call this function from the MonoBehaviour.Update function, since the state gets reset each frame. It will not return true until the user has released the mouse button and pressed it again. button values are 0 for left button, 1 for right button, 2 for the middle button.

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-click.");

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

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