check if text box is empty then run code

Question

I have the following jquery and want to check if the text box is empty before the code is run:

<script type="text/javascript">
    $(document).ready(function () {
        if ($("#FNameTB").val().length < 0) {
            $("input#FNameTB").labelify({ labelledClass: "greylabel" });
        }       
</script>

but its not working.

aziz punjani · Accepted Answer · 2012-09-07 18:19:40Z

13

Length will never be less than 0.

if ( $("#FNameTB").val().length === 0 )

You can even add in a trim() to be thorough

if ( $("#FNameTB").val().trim().length === 0 )

edited Sep 7, 2012 at 18:19

answered Sep 8, 2011 at 15:36

aziz punjani

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1 Comment

Bill Criswell Over a year ago

Indeed. Less than 0 isn't possible here which is what your condition is testing.

Jason Gennaro · Accepted Answer · 2011-09-08 15:36:18Z

1

Try

if ($("#FNameTB").val() == '')

answered Sep 8, 2011 at 15:36

Jason Gennaro

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Comments

JaredPar · Accepted Answer · 2011-09-08 15:37:46Z

0

Try the following

if ($('#FNameTB').val() === '') { 
  // It's empty
}

answered Sep 8, 2011 at 15:37

JaredPar

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