passing php tag into javascript code example

Example 1: javascript php variable

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

Example 2: how to use php echo data in javascript

<?php
$php_variable = 'string'; //Define our PHP variable. You can of course get the value of this variable however you need.
?>			
        <script> js_variable_name = "<?php echo $php_variable; ?>";</script>