21st May, 2014

Reliably detect IE version with JavaScript

I found this snippet online to detect what version of IE using JavaScript. I didn't write it, if this is yours, please let me know and I'll attribute you.

function getInternetExplorerVersion() {
    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;


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