how to test if a php variable has value in jquery

Question

i want to use the value of a php variable within a jquery ajax function. i however first need to test if the variable has value.

i know that i can test the length of a object like this:

if ($(selector).length)

i am not sure how i can test if a jquery variable has value. below is my test;

 $idAjax = 15;

<script>
jQuery(document).ready(function(){

 function ajaxMessagesCount(){   

      var  theData =  <?php echo $idAjax ?>;

  if (theData.length){
//do somting
}

})
</script>

The only jQuery you have is the document.ready. The rest is plain JavaScript — mplungjan, Aug 04 '15 at 08:41
I think you just need to enclose with double quotes. Then your test will work just fine. — Neil Villareal, Aug 04 '15 at 08:46
No he does not. See other answers and their comments. The value is an integer — mplungjan, Aug 04 '15 at 08:46
even though it is an integer the fact that it is enclose with double qoute it will be converted to string so checking the length of the variable will work just fine. — Neil Villareal, Aug 04 '15 at 08:47
Sure, but then he needs to convert it to get it back to a number. `if (typeof theData == "undefined")` will handle either — mplungjan, Aug 04 '15 at 09:01

score 0 · Answer 1 · edited Aug 04 '15 at 08:41

0

If you want to check if variable exists, and it's not empty, try this:

if (typeof variable !== 'undefined' && variable)

edited Aug 04 '15 at 08:41

Mihai Matei

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answered Aug 04 '15 at 08:37

Daimos

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Your code will fail if the value of the $idAjax is falsy. Such as the valid value `0` – mplungjan Aug 04 '15 at 08:42
if its valid value it ok to use only typeof part – Daimos Aug 04 '15 at 10:43

how to test if a php variable has value in jquery

1 Answers1