如何用javascript检测IE6？

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 xx 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
}

Answer 2

If you have access to the code, I suggest conditional comments . It's 100% and less JavaScript.

<!--[if IE 6]>
<script type="text/javascript">
var IE6 = true;
</script>
<![endif]-->

If not, traditional JavaScript methods include analyzing navigator or other object detection to sniff out the browser.

Answer 3

Conditional comments is easily the best approach, as suggested by Jason McCreary. It is possible to use conditional comments with just JavaScript as follows:

var div = document.createElement("div");
div.innerHTML = "<!--[if lte IE 6]><i></i><![endif]-->";
var isIe6orLower = !!div.getElementsByTagName("i").length;

alert("Is IE 6 or lower: " + isIe6orLower);