Javascript document getElementById id value returning null instead of empty string when the element is an empty text box

Question

I have a text box element whose value I am trying to access using document getElementById  id-name   value  I find that the call is returning a null instead of empty string  The data-type of the returned value is still string  Is null a string value    lt input type  text  value    id  mytext  gt  is the textbox whose value I am trying to fetch using var mytextvalue   document getElementById  mytext   value

User · Answer

Please check this fiddle and let me know if you get an alert of null value  I have copied your code there and added a couple of alerts  Just like others  I also dont see a null being returned  I get an empty string  Which browser are you using

User · Answer

fyi  this can happen if you are using the html type  number  attribute on your input tag   Entering a non-number will clear it before your script knows what s going on

User · Answer

This demo is returning correctly for me in Chrome 14  FF3 and FF5  with Firebug    var mytextvalue   document getElementById  mytext   value  console log mytextvalue            true console log mytextvalue    null      false   and changing the console log to alert  I still get the desired output in IE6

User · Answer

I think the textbox you are trying to access is not yet loaded onto the page at the time your javascript is being executed   ie   For the Javascript to be able to read the textbox from the DOM of the page  the textbox must be available as an element  If the javascript is getting called before the textbox is written onto the page  the textbox will not be visible and so NULL is returned

User · Answer

try this         lt script type  text javascript  gt      function test        var av document getElementById  mytext   value      alert av              lt  script gt        lt input type  text  value    id  mytext  gt       lt input type  button  onclick  test    value  go    gt

User · Answer

It seems that you ve omitted the value attribute in HTML markup   Add it there as  lt input value         gt

User · Answer

For your code  var mytextvalue   document getElementById  mytext      mytextvalue will contain null if you have a document write   statement before this code  So remove the document write statement and you should get a proper text object in the variable mytextvalue   This is caused by document write changing the document

User · Answer

Posting your HTML might help a bit  Instead  you can get the element first and then check if it is null or not and then ask for its value rather than just asking for the value directly without knowing if the element is visible on the HTML or not   element1   document getElementById id    if element1    null          code to set the value variable

[javascript] Javascript document.getElementById("id").value returning null instead of empty string when the element is an empty text box

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