HTML 常用确难搜到的文档

1.滚动到指定位置触发时间

            $(function() {
                var getDiv_md = $("#vvdeio");
                var offSet = getDiv_md.offset().top;
                $(window).scroll(function(){
                    if ($(window).scrollTop() > offSet){
                        console.log(1111);
                    }else{
                        console.log(2222);
                    }
                })
            })

JS建立缓存

<script>
//设置cookie
function setCookie(cname, cvalue, exdays) {
 var d = new Date();
 d.setTime(d.getTime() + (exdays*24*60*60*1000));
 var expires = "expires="+d.toUTCString();
 document.cookie = cname + "=" + cvalue + "; " + expires;
}

//获取cookie
function getCookie(cname) {
 var name = cname + "=";
 var ca = document.cookie.split(';');
 for(var i=0; i<ca.length; i++) {
  var c = ca[i];
  while (c.charAt(0)==' ') c = c.substring(1);
  if (c.indexOf(name) != -1) return c.substring(name.length, c.length);
 }
 return "";
}

//清除cookie 
function clearCookie(name) { 
 setCookie(name, "", -1); 
} 

function checkCookie() {
 var user = getCookie("username");
 if (user != "") {
  alert("Welcome again " + user);
 } else {
  user = prompt("Please enter your name:", "");
  if (user != "" && user != null) {
   setCookie("username", user, 365);
  }
 }
}
checkCookie(); 
</script>