Question

Why is this not working?

<?php 

mysqli_select_db($connect,"dev");
$response = "Select response from revbut where session='$u'";
$rquery  =  mysqli_query($connect,$response);

$responseanswer = mysqli_fetch_array($rquery);
$re  = $responseanswer['response'];
?>

<script type="text/javascript">
<?php echo $re; ?>
</script>

$re inside JavaScript is not getting echoed. But if I place it inside the above PHP function, it is getting echoed.

EDIT – BUT THEN WHY IS THIS NOT WORKING?

if(<?php echo $re; ?>){
    document.getElementById('hide').style.display = "none";
}

if I PLACE the hide function outside the if – it is working.

Answer 1

It get’s echoed, but you won’t see anything on your page as the text will be written within the Javascript-tag which is not displayed by the browser. Look at your page source to verify that the text is really there.

EDIT

Try

if(<?php echo json_encode($re); ?>){
    document.getElementById('hide').style.display = "none"; 
}

This will ensure that your PHP string will be converted into the appropriate Javascript type – in case of strings it’ll ensure that the string is enclosed in " and is escaped properly.

EDIT again

When you do the following

<script type="text/javascript"> 
if(<?php echo $re; ?>){
    document.getElementById('hide').style.display = "none"; } 
</script>

this is what is written to the HTML page (that’s then interpreted by the browser)

<script type="text/javascript"> 
if(whatever is in the $re vairable){
    document.getElementById('hide').style.display = "none"; } 
</script>

But this is not even valid Javascript. What you want is

<script type="text/javascript"> 
if("whatever is in the $re vairable"){
    document.getElementById('hide').style.display = "none"; } 
</script>

Note the " which ensures that the whole thing is valid Javascript and that the contents of $re will be interpreted as an Javascript string by the Browser’s Javascript engine. The call to json_encode() does exactly this – it transforms PHP variables into the appropriate Javascript variables.