Last keyup event on delete not fired jquery

Question

I have a strange behavior with the "keyup" event: When i fill out an input field with something, then i delete the value, the last delete keyup event isn't recognised.

Example code:

$('#input').on('keyup',function(){
 if($(this).val().length > 0){
    $('#text').html($(this).val())
 }
});

Fiddle HERE

Any solution or why this strange behavior?

Answer 1

UPDATE

According to the new problem described in the fiddle the solution can be based on jQuery data:

$(function () {
  $('#input-deposit').on('keyup', function (e) {
    if ($(this).val().length >= 0) {
      $('#text').html($(this).val())
    }
  });

  // set the default of previousValue
  $('#input-deposit').data('previousValue', 0);

  $('#input-deposit').on('keyup', function (e) {
    var t = 2000;

    if (!isNaN(this.value) && this.value.length != 0) {
      // get the previous value
      var previousValue = parseFloat($('#input-deposit').data('previousValue'));
      var total = parseFloat($('#input-balance').val());
      var deposit = parseFloat($(this).val());
      $('#input-deposit').data('previousValue', deposit);
      // use previousValue
      t = total + previousValue - deposit;
    } else {
      // reset previousValue
      $('#input-deposit').data('previousValue', 0);
    }
    $('#input-balance').val(t.toFixed(2));
  });
});

<script src="https://code.jquery.com/jquery-1.12.4.min.js"></script>

<label>Deposit</label>
<input type="text" value="" id="input-deposit"/>
<label>Balance</label>
<input type="text" value="2000" id="input-balance"/>

<div id="text"></div>

The problem is:

if($(this).val().length > 0){

This must be:

if($(this).val().length >= 0){

Snippet:

$(function () {
  $('#input').on('keyup',function(){
    if($(this).val().length >= 0){
      $('#text').html($(this).val())
    }
  });
});

<script src="https://code.jquery.com/jquery-1.12.4.min.js"></script>

<input type="text" value="" id="input"/>
<div id="text"></div>