How to update event handlers from a Handlers List?

Question

(How to update event handlers from a Handlers List)>> with incremental index as event occurs ?

For skilled programmer the solution to my problem may be obvious :
* * *
<<JQuery >>
var index = ;
var array = [] ;
var elemArr = array[index] ; // §1 << which does get updated
$(function() { /*some code*/ ; index++ ; /* if §1 here too, it turns "undefined" */ ; })
<<//JQuery >>

*** *** ***
I do not understand why do I get "undefined" instead of the next array value...
And I do not find out how to get it within 1 or 2 more statements max. ...

Could you help me :-) ?

*** The real problem leans on this example in the linked code below : ***

https://code.sololearn.com/W79Pr7vNTZpo/#html

Answer 1

Is this?!
https://code.sololearn.com/W5VFZ7q6mmdx/#html

Answer 2

Or this?
https://code.sololearn.com/WIzOI5N2RB16/#html