how to make a gameobject do something when clicked unity code example

Example 1: unity onclick object

void Update () {
     
 }
  void OnMouseDown(){
         // this object was clicked - do something
     Destroy (this.gameObject);
  }

Example 2: unity click object

void OnMouseDown()
{         
	// this object was clicked - do something     
    Destroy (this.gameObject);  
}