Question

How I do to detect the internet explorer and lower versions using javascript? I know about the navigator object, but what is the information that it send to identify him?

Answer 1

I recommend using conditional comments to the load the CSS or JS targeted for IE x.x as @Jason McCreary suggests. However, if you’re deep in the code of a JS plug-in or something and need it for JS, this is a pretty sure fire way of getting it done:

function getInternetExplorerVersion()
// Returns the version of Internet Explorer or a -1
// (indicating the use of another browser).
{
  var rv = -1; // Return value assumes failure.
  if (navigator.appName == 'Microsoft Internet Explorer')
  {
    var ua = navigator.userAgent;
    var re  = new RegExp("MSIE ([0-9]{1,}[\.0-9]{0,})");
    if (re.exec(ua) != null)
      rv = parseFloat( RegExp.$1 );
  }
  return rv;
}

And if you’re a minimalist, a bit of a rebel; this method I believe actually works:

if (typeof document.body.style.maxHeight != "undefined") {
    // IE 7, moz, saf, opera 9
    } else{
    // IE6, older browsers
}