pass php variable to javascript

<script>
'var name = <?php echo json_encode($name); ?>;
</script>'//passing PHP variable to JavaScript
var myJSVar = <?php echo json_encode($myPHPVar); ?>;<?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>
<script>
   var res = "success";
</script>
<?php
   echo "<script>document.writeln(res);</script>";
?>