How to get old Value with onchange event in text box

Question

I have a text Box and a Value poplulated in it when page loads  Now If user chanegs any thing in text box  then I want to get the Changed Value New Value  and Old Value but when I do ELEMENT value then its giving only changed Value  any Suggestions to get old value   below is my code    lt head gt       lt script type  text javascript  gt        function onChangeTest changeVal            alert  Value is     changeVal value                lt  script gt     lt  head gt     lt body gt       lt form gt         lt div gt             lt input type  text  id  test  value   ABS  onchange  onChangeTest this   gt           lt  div gt       lt  form gt     lt  body gt   lt  html gt    Thanks in Advance

User · Answer

You should use HTML5 data attributes  You can create your own attributes and save different values in them

User · Answer

You ll need to store the old value manually   You could store it a lot of different ways   You could use a javascript object to store values for each textbox  or you could use a hidden field  I wouldn t recommend it - too html heavy   or you could use an expando property on the textbox itself  like this    lt input type  text  onfocus  this oldvalue   this value   onchange  onChangeTest this  this oldvalue   this value     gt    Then your javascript function to handle the change looks like this        lt script type  text javascript  gt      function onChangeTest textbox            alert  Value is     textbox value     n     Old Value is     textbox oldvalue              lt  script gt

User · Answer

I am not sure  but maybe this logic would work   var d   10  var prevDate       var x   0  var oldVal       var func   function  d        if  x    0  amp  amp  d    prevDate  amp  amp  prevDate                  oldVal   d          prevDate   d            else if  x    1  amp  amp  prevDate    d            oldVal   prevDate          prevDate   d            console log oldVal       x   1                                                                       Try           func 2            func 3            func 4

User · Answer

You can do this  add oldvalue attribute to html element  add set oldvalue when user click  Then onchange event use oldvalue    lt input type  text  id  test  value   ABS  onchange  onChangeTest this   onclick  setoldvalue this   oldvalue    gt    lt script gt  function setoldvalue element      element setAttribute  oldvalue  this value      function onChangeTest element      element setAttribute  value  this getAttribute  oldvalue        lt  script gt

User · Answer

Maybe you can store the previous value of the textbox into a hidden textbox  Then you can get the first value from hidden and the last value from textbox itself  An alternative related to this  at onfocus event of your textbox set the value of your textbox to an hidden field and at onchange event read the previous value

User · Answer

Maybe you can try to save the old value with the  onfocus  event to afterwards compare it with the new value with the  onchange  event

User · Answer

A dirty trick I somtimes use  is hiding variables in the  name  attribute  that I normally don t use for other purposes     select onFocus  this name this value  onChange someFunction this name this value  gt  lt option      Somewhat unexpectedly  both the old and the new value is then submitted to someFunction oldValue newValue

User · Answer

I would suggest   function onChange field     field old field recent    field recent field value       we have available old value here

User · Answer

element defaultValue will give you the original value   Please note that this only works on the initial value   If you are needing this to persist the  old  value every time it changes  an expando property or similar method will meet your needs

[javascript] How to get old Value with onchange() event in text box

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