javascript - Getting lastIndexOf on a Dropdown -

My attempt is to get the last item in the dropdown and check it out

  if ( Day.lastIndexOf (day.length) == 28) {..do something}  

The day var is set in the dropdown control context. Obviously I am not doing this right. How do I know how I can apply the last index to a dropdown list? How do I get the array? I also tried it, but it does not work, syntax error:

  day.points.Also indexoff (day.line)  

it seems Will it work, the option I believe is an array of values ​​... is

seafried,

You are probably trying to do this :

The last index () method returns the state of the last event of a specified string value,

P>

  if (option .days.options. Length-1] .value == 28) {...}