1、js判断移动端系统

var userAgent = navigator.userAgent;
// android终端
var isAndroid = userAgent.indexOf('Android') > -1 || userAgent.indexOf('Adr') > -1;
// ios终端
var isIOS = !!userAgent.match(/\(i[^;]+;( U;)? CPU.+Mac OS X/);

2、js判断是否PC端

function IsPC() {
    var userAgent = navigator.userAgent;
    var Agents = ["Android", "iPhone", "SymbianOS", "Windows Phone", "iPad", "iPod"];
    var flag = true;
    for (var v = 0; v < Agents.length; v++) {
        if (userAgent.indexOf(Agents[v]) > -1) {
            flag = false;
            break;
        }
    }
    return flag;
}

3、js判断是否为微信内置浏览器

function isWeiXin() {
    var userAgent = window.navigator.userAgent.toLowerCase();
    if(userAgent.match(/MicroMessenger/i) == 'micromessenger') {
        return true;
    } else {
        return false;
    }
}

4、js判断是否为ie浏览器，并返回相应状态

function IEVersion() {
    // 取得浏览器的userAgent字符串
    var userAgent = navigator.userAgent;
    // 判断是否IE<11浏览器
    var isIE = userAgent.indexOf("compatible") > -1 && userAgent.indexOf("MSIE") > -1;
    // 判断是否IE的Edge浏览器  
    var isEdge = userAgent.indexOf("Edge") > -1 && !isIE;
    // 判断是否为IE11浏览器  
    var isIE11 = userAgent.indexOf('Trident') > -1 && userAgent.indexOf("rv:11.0") > -1;
    if(isIE) {
        var reIE = new RegExp("MSIE (\\d+\\.\\d+);");
        reIE.test(userAgent);
        var fIEVersion = parseFloat(RegExp["$1"]);
        if(fIEVersion == 7) {
            return 7;
        } else if(fIEVersion == 8) {
            return 8;
        } else if(fIEVersion == 9) {
            return 9;
        } else if(fIEVersion == 10) {
            return 10;
        } else {
            return 6; // IE版本<=7
        }   
    } else if (isEdge) {
         return 'edge'; // edge
    } else if (isIE11) {
        return 11; // IE11  
    } else {
        return -1; // 不是ie浏览器
    }
}

5、js判断浏览器内核

var browserInfo = {
    versions: function () {
        var userAgent = navigator.userAgent, 
            appVersion = navigator.appVersion;
        return {
            // IE内核
            trident: userAgent.indexOf('Trident') > -1,
            // opera内核
            presto: userAgent.indexOf('Presto') > -1,
            // 苹果、谷歌内核
            webKit: userAgent.indexOf('AppleWebKit') > -1,
            // 火狐内核
            gecko: userAgent.indexOf('Gecko') > -1 && userAgent.indexOf('KHTML') == -1,
            // 是否为移动终端
            mobile: !!userAgent.match(/AppleWebKit.*Mobile.*/),
            // ios终端
            ios: !!userAgent.match(/\(i[^;]+;( U;)? CPU.+Mac OS X/),
            // android终端
            android: userAgent.indexOf('Android') > -1 || userAgent.indexOf('Adr') > -1,
            // 是否为iPhone或者QQHD浏览器
            iPhone: userAgent.indexOf('iPhone') > -1,
            // 是否iPad
            iPad: userAgent.indexOf('iPad') > -1,
            // 是否web应该程序，没有头部与底部
            webApp: userAgent.indexOf('Safari') == -1,
            // 是否微信 （2015-01-22新增）
            weixin: userAgent.indexOf('MicroMessenger') > -1,
            // 是否QQ
            qq: userAgent.match(/\sQQ/i) == " qq"
        };
    },
    language:(navigator.browserLanguage || navigator.language).toLowerCase()
}

6、js判断客户端操作系统

function detectOS() {
    var userAgent = navigator.userAgent;
    var isWin = (navigator.platform == "Win32") || (navigator.platform == "Windows");
    var isMac = (navigator.platform == "Mac68K") || (navigator.platform == "MacPPC") || (navigator.platform == "Macintosh") || (navigator.platform == "MacIntel");
    if (isMac) return "Mac";
    var isUnix = (navigator.platform == "X11") && !isWin && !isMac;
    if (isUnix) return "Unix";
    var isLinux = (String(navigator.platform).indexOf("Linux") > -1);
    if (isLinux) return "Linux";
    if (isWin) {
        var isWin2K = userAgent.indexOf("Windows NT 5.0") > -1 || userAgent.indexOf("Windows 2000") > -1;
        if (isWin2K) return "Win2000";
        var isWinXP = userAgent.indexOf("Windows NT 5.1") > -1 || userAgent.indexOf("Windows XP") > -1;
        if (isWinXP) return "WinXP";
        var isWin2003 = userAgent.indexOf("Windows NT 5.2") > -1 || userAgent.indexOf("Windows 2003") > -1;
        if (isWin2003) return "Win2003";
        var isWinVista= userAgent.indexOf("Windows NT 6.0") > -1 || userAgent.indexOf("Windows Vista") > -1;
        if (isWinVista) return "WinVista";
        var isWin7 = userAgent.indexOf("Windows NT 6.1") > -1 || userAgent.indexOf("Windows 7") > -1;
        if (isWin7) return "Win7";
        var isWin10 = operatingInfo.indexOf("Windows NT 10")!=-1;
        if(isWin10) return "Win10"
    }
    return "other";
}
document.writeln("您的操作系统是：" + detectOS());