测试定时器
<html>
<head>
<meta charset="UTF-8">
<title></title>
<style>
#txt{
300px;
height:300px;
display: block;
margin:100px auto;
}
</style>
<script>
window.onload=function(){
var oTxt=document.getElementById("txt");
var timer=null;
var oldT=new Date().getTime(); //老时间
timer=setInterval(function(){
var now=new Date().getTime(); //新时间
oTxt.value+=now-oldT+'
'; //存放时间差
oldT=new Date().getTime();
},1000);
document.onclick=function(){
clearInterval(timer);
}
}
</script>
</head>
<body>
<textarea id="txt" rows="30" cols="30"></textarea>
</body>
</html>
获取字符串的字节长度:
<html>
<head>
<meta charset="utf-8">
<title></title>
<script>
var str='abc啊';
function getByLon(str,type){
var res=0;
for(var i=0;i<str.length;i++){
if(str.charAt(i)>='u4e00'&&str.charAt(i)<='u9fa5'){ //在4e00到9fa5之间的字符
if(type=='utf-8'){ //utf-8,字符加3
res+=3;
}else{res+=2;} //其他字符加2
}else{res++} //不在4e00到9fa5之间的字符
}
return res;
}
alert(getByLon(str,'utf-8'));
</script>
</head>
<body>
</body>
</html>