php isset $ _SESSION等效于JS

Question

I have this snippet of code in php:

   var flip1 = <?php echo (isset($_SESSION['static']) && isset($_SESSION['static']['1'])) ? 1 : -1; ?>;
   var flip2 = <?php echo (isset($_SESSION['static']) && isset($_SESSION['static']['2'])) ? 2 : -1; ?>;
   var flip3 = <?php echo (isset($_SESSION['static']) && isset($_SESSION['static']['3'])) ? 3 : -1; ?>;


if(!isset($_SESSION['static']) || !isset($_SESSION['static']['1'])){
    $_SESSION['static']['1']['is_smoke'] = 1;
    $_SESSION['static']['1']['content'] = 'Testing Content';
}else if(!isset($_SESSION['static']) || !isset($_SESSION['static']['2'])){
    $_SESSION['static']['2']['is_smoke'] = 0;
    $_SESSION['static']['2']['content'] = 'Testing Content Testing Content.';
}else if(!isset($_SESSION['static']) || !isset($_SESSION['static']['3'])){
    $_SESSION['static']['3']['is_smoke'] = 1;
    $_SESSION['static']['3']['content'] = 'Testing Content Testing Content Testing Content.';
}

I was wondering how do I rewrite this in JS/Jquery. Is there a way to execute this similar process in JS/Jquery?