$(".whitebox").on('change', function () {
       var previousAmt = $(this).data("old"); //  i want previous value
        var id = this.id;
        var slpitid = id.split("_");

        var checkboxid = "#chck_" + slpitid[0];
        if ($(checkboxid).is(':checked')) {
            var tipFlag = true;
        }
        else {
            var tipFlag = false;
        }

        if (tipFlag === true)
        {
            $("#amounttipchange").modal('show');
        }
        //alert(previousAmount);
    });

 $(".whitebox").on('change', function () {
       var previousAmt = $(this).data("old"); //  i want previous value
        var id = this.id;
        var slpitid = id.split("_");

        var checkboxid = "#chck_" + slpitid[0];
        if ($(checkboxid).is(':checked')) {
            var tipFlag = true;
        }
        else {
            var tipFlag = false;
        }

        if (tipFlag === true)
        {
            $("#amounttipchange").modal('show');
        }
        //alert(previousAmount);
    });

i want to store previous value on change event how can i perform in jquery i am not able to store value using $(this).data("old"); any help will be appreciated

• javascript
• jquery

Share Improve this question Follow edited Jul 6, 2017 at 15:26 Inian 86.2k1515 gold badges163163 silver badges181181 bronze badges asked Jul 6, 2017 at 14:32 user6885473user6885473 32811 gold badge55 silver badges2525 bronze badges 3

• Please add your HTML code too – Ionut Necula Commented Jul 6, 2017 at 14:33
• i am not able to store value using $(this).data("old") -- why? – Steve Danner Commented Jul 6, 2017 at 14:34
• previousAmt =$(this).data("old") output is emtpty – user6885473 Commented Jul 6, 2017 at 14:40

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3 Answers 3

Sorted by: Reset to default 3

You almost got this right, but you forgot to update the data-old in your code, below is an example and jsbin

 $(".whitebox").on('change', function (event) {
   // on first change will be empty string
   // as no previous value was set
   var oldValue = event.target.dataset.old;
   console.log('old value', oldValue);

   // your code here

   // at the end assign new value to data-old attribute
   $(this).data('old', event.target.value);
   console.log(event.target.value);
 });

http://jsbin./jasaqiwuwo/

Try this:

$("#checkboxid").on('click',function(){
   $(this).data('old',$(this).val());
});

And then use your change event.

var prevVal = $('input').val(); //init val
var valuesHistory = [prevVal]; 
$('input').data('prevData', prevVal);

$('input').on('change', function() {
  console.log('prev value from data: ', $(this).data('prevData'));
  console.log('prev value from var: ', prevVal);
  console.log('log: ', valuesHistory);
  valuesHistory.push($('input').val());
  $('input').data('prevData', $('input').val());
  prevVal = $(this).val();
});
// you can also get the prev value, like that valuesHistory[valuesHistory.length-2];

<script src="https://ajax.googleapis./ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<input type="text">