Get IE version

ieversion.js

// determine Internet Explorer version
// add class 'ieX' to html
window.ieVersion = (function() {
  var ddm = document.documentMode;
  var html = document.documentElement;
  if (Math.round(ddm) === ddm){
    if (html.classList) {
      html.classList.add('ie' + ddm);  
    } else {
      html.className += ' ie' + ddm;
    }
    return ddm;
  }
}());