Input文本框随着输入内容多少自动延伸

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 
<html xmlns="http://www.w3.org/1999/xhtml"> 
<head> 
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> 
<title>无标题文档</title> 
<script language="javascript"> 
function checkLength(which) { 
    var oTextCount = document.getElementById("char");    
    iCount = which.value.replace(/[^/u0000-/u00ff]/g,"aa"); 
    oTextCount.innerHTML = "<font color=#FF0000>"+ iCount.length+"</font>"; 
    which.style.border = '1px dotted #FF0000'; 
which.size=iCount.length+2; 
} 
 </script> 
</head> 
<body> 
<input name="words" size="2"    onkeyup="checkLength(this)"/> 
    <span id="char">0</span>个字符 
</body> 
</html> 
原文地址:https://www.cnblogs.com/wsir/p/6117993.html