Conditional IE Code to add class in body tag in Javascript

Conditional IE Code to add class in body tag in Javascript -

var ms_ie = false;
var ua = window.navigator.userAgent;
var old_ie = ua.indexOf('MSIE ');
var new_ie = ua.indexOf('Trident/');
   
if ((old_ie > -1) || (new_ie > -1)) {
    ms_ie = true;
}
   
if ( ms_ie ) {
    $('body').addClass('ie');
}