Closure in for loop problem

 for (int i = 0; i < buttons.Length; i++)
        {
            var i1 = i;
            buttons[i].onClick.AddListener(() => OnButtonClick(buttons[i1]));
        }


 for (int i = 0; i < buttons.Length; i++)
        {
            buttons[i].onClick.AddListener(() => OnButtonClick(buttons[i]));
        }