如何用JS判断用户输入了多少个字节HTMLHEAD TITLEtest/TITLE meta http-equivcontent-type cont
如何用JS判断用户输入了多少个字节
<HTML><HEAD> <TITLE>test</TITLE> <meta http-equiv=content-type content="text/html; charset=UTF-8"> <script language=javascript> function test(){ var testInput=document.getElementById("test").value; var len=testInput.len() ;alert(len);if(len>600)alert("超过限制"); }String.prototype.len = function() {//xxx表示一个字符占的长度(字节数).utf-8是3个return this.replace(/[^\x00-\xff]/g, 'xxx').length; }; </script> </head> <body> <div><input type=text id="test" /><input type=button value="测试" onclick=test()></div></body> </html>?