(function() {
    var OriginTitile = document.title, titleTime;
    document.addEventListener(‘visibilitychange‘, function() {
        if (document.hidden) {
            document.title = ‘切換瀏覽器窗口‘;
            clearTimeout(titleTime);
        } else {
            document.title = ‘切回來‘;
            titleTime 
 
= setTimeout(function() {
                document.title = OriginTitile;
            },2000);
        }
    });
})();

當用戶切換了窗口後改變title，感覺挺有趣的，收藏了