unity if button clicked code example

Example 1: unity if gameobject is clicked

void OnMouseDown() 
 {
   Debug.Log("Mouse is down")
 } 

 void OnMouseUp() 
 {
   Debug.Log("Mouse is up")
 } 

 void OnMouseClick() 
 {
   Debug.Log("Mouse is clicked (down then up its 1 click)")
 } 

// Works only if the gameobject have a collider

Example 2: unity Check if mouse clicked UI element

EventSystem.current.IsPointerOverGameObject()