Stop rotating for a click right on the game object - rotation

Question

I have a unity game and in it, a rotating game object, which increases its speed when it is clicked.
My problem is that the game does not work as I want it to. Right now, if I click any part of the screen, it increases the game object's speed of rotation. On the other hand, if I keep my finger on the screen, the game object starts to slow down and then starts rotating in the opposite direction.
I want the rotation of the object to increase when I click on it, not just if I click on any part of the screen. Furthermore, I don't know why holding down reverses the direction of rotation.
var speed = 1;
var click = 0;
Screen.orientation = ScreenOrientation.LandscapeLeft;
function Update (){
{
transform.Rotate(0,0,speed);
}
if(Input.GetMouseButton(0))
{
if(speed != 0)
{
speed = 0;
} else {
click++;
speed = click;
}

Answer 1

You must use Input.GetMouseButtonUp or Input.GetMouseButtonDown, NOT A Input.GetMouseButton, this method used for clamping.
Try use this code:
var speed = 1;
var click = 0;
Screen.orientation = ScreenOrientation.LandscapeLeft;
function Update (){
{
transform.Rotate(0,0,speed);
}
if(Input.GetMouseButtonDown(0))
{
if(speed != 0)
{
speed = 0;
} else {
click++;
speed = click;
}

Answer 2

A few issues here:
Firstly:
To increase speed upon clicking on the object only, use raycasting from camera, and check if it hits your object. Your object needs need a collider component on it for this to work.
RaycastHit hit;
Ray ray = camera.ScreenPointToRay(Input.mousePosition);
if (Physics.Raycast(ray, out hit))
{
Transform objectHit = hit.transform;
objectHit.Rotate(0,0,speed);
}
Refer to https://docs.unity3d.com/Manual/CameraRays.html -> Raycasting section, for more information.
Secondly:
Input.GetMouseButtonDown(..) // returns true at the instance your mouse button transits from up to down
Input.GetMouseButton(..) // returns true as long as your mouse button is held down
Use Input.GetMouseButtonDown(..) in your Update() method if you want to to do something when you click on it.