Get Internet Explorer version and get is Edge Navigator in javascript

ieVersion.js

/**
 * Gets the internet explorer version.
 *
 * @return {int} The internet explorer version.
 */
function getInternetExplorerVersion() {
    var rv = -1;

    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);
        }
    } else if (navigator.appName == 'Netscape') {
        var ua = navigator.userAgent;
        var re  = new RegExp("Trident/.*rv:([0-9]{1,}[\.0-9]{0,})");

        if (re.exec(ua) != null) {
            rv = parseFloat(RegExp.$1);
        }
    }

    return rv;
}

isEdge.js

/**
 * Determines if edge navigator.
 *
 * @return {boolean} True if edge navigator, False otherwise.
 */
function isEDGENavigator(){
    var isEdge = false;

    if(navigator.appName == "Netscape"){
        isEdge = (navigator.appVersion.indexOf('Edge') > -1);
    }

    return isEdge;
}