[JS] Detect browser version

function get_browser_info() {
  var ua = navigator.userAgent, tem, M = ua.match(/(opera|chrome|safari|firefox|msie|trident(?=\/))\/?\s*(\d+)/i) || [];
  if (/trident/i.test(M[1])) {
    tem = /\brv[ :]+(\d+)/g.exec(ua) || [];
    return {name: 'IE ', version: (tem[1] || '')};
  }
  if (M[1] === 'Chrome') {
    tem = ua.match(/\bOPR\/(\d+)/)
    if (tem != null) {
      return {name: 'Opera', version: tem[1]};
    }
  }
  M = M[2] ? [M[1], M[2]] : [navigator.appName, navigator.appVersion, '-?'];
  if ((tem = ua.match(/version\/(\d+)/i)) != null) {
    M.splice(1, 1, tem[1]);
  }
  return {
    name: M[0],
    version: M[1]
  };
}

var browser = get_browser_info();
console.log(browser.name);
console.log(browser.version);