var currentTimeArray = [];

  function currentTime(){

    var time = moment();

    return currentTimeArray.push(time);

  }



  $('.next-fieldgroup').on('click', function(e){

    e.preventDefault();

    currentTime();



    var endTime = $(currentTimeArray).last();

    var startTime = currentTimeArray[0];

    var duration = moment.duration(endTime.diff(startTime));

    var elapsedTime = duration().asMinutes();



    $('#timer-counter').text( elapsedTime );

  });

What it is supposed to do...

1. on click store NOW time in to ARRAY


2. on click compare arr[0] with arr.last() to get time elapsed time


3. update div with elapsed time in minutes

I expect the output to like:

Time elapsed: 12 minutes

I get the following error:

Uncaught TypeError: undefined is not a function