js判断是pc端还是移动端

<script type="text/javascript">
    //平台、设备和操作系统
    var system = {
        win : false,
        mac : false,
        xll : false
    };
    //检测平台
    var p = navigator.platform;
    system.win = p.indexOf("Win") == 0;
    system.mac = p.indexOf("Mac") == 0;
    system.x11 = (p == "X11") || (p.indexOf("Linux") == 0);
    if (system.win || system.mac || system.xll) {
        //进入pc页面
        window.location.href = "https://www.baidu.com/";
    } else {
        //进入移动端页面
        window.location.href = "http://m2.cn.bing.com/";
    }
</script>