how do i access php variables so that i can work with the values using javascript/ jquery?

Question

Question is on how to work with php variables in a webpage, using javascript/jquery. The following code represents the scenario.

PHP Code Snippet for pagination -

if($current_page>1)
$previous = $current_page - 1;          
else
$previous = $current_page;          

if($current_page==$num_pages)
$next = $current_page;          
else
$next = $current_page + 1;  

//the line below is for right arrow link - go to next page
<?php echo '<a href="gallery.php?p=' .$next. '">    
<img src="Arrow-Right.png" width="16" height="16" title="Next Page" /> </a>';   
?>

//the line below is for left arrow link - go to previous page
<?php echo '<a href="gallery.php?p=' .$previous. '">    
<img src="Arrow-Left.png" width="16" height="16" title="Previous Page" /> </a>';    
?>

Now my question - I want to disable the left and right arrow links based on the condition - if $current_page = $num_pages (meaning, if max page has reached), then use javascript to disable the right arrow link if $current_page = 1 (meaning, if min page has reached), then use javascript to disable the left arrow link

Pretty simple scenario for pagination, but my concern is over how to use the variables correctly, since $current_page, $num_pages etc..are all PHP variables, and I assume they cannot be accessed readily in any Javascript code. So how do i access them, so that I can use JS to further work on link enabling/disabling or css styling using js etc...

Appreciate any pointers on the above.

Answer 1

<?php

$next_page = 12;

echo "<script>var next_page=$next_page;</script>"

Javascript variable next_page will be ready for use.

Answer 2

<?php
  echo '<script>pagenum=' . $num_pages . ';current_page=' . $current_page . ';</script>';
?>

Answer 3

Just echo your values into javascript:

<script>
   var jsvarname = "<?php echo $phpvarname; ?>";
</script>

I assume you know that javascript is client side and php server side, and what that means?

Answer 4

If you don't want the variables showing up in when the page source is viewed, you could store the information in a cookie.

Be aware that it's trivial to look at the contents of a cookie, however.