<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>jQuery实现限制input框 textarea文本框输入字符数量的方法</title>
</head>
<script src="http://j2.58cdn.com.cn/js/jquery-1.8.3.js"></script><!--依赖jquery-->
<body>
用户名:<input type="text" name="username" id="username" >
<span style="display:none;border:0;float:right;margin-right:50px" id="t2" >用户名长度为3-6位</span>
<!--我微信号 (WX-APP-PC) -->
<script>
(function($) {
$.fn.extend( {
limiter: function(limit, elem) {
$(this).on("keyup focus", function() {
setCount(this, elem);
});
function setCount(src, elem) {
var chars = src.value.length;
if (chars > limit) {
src.value = src.value.substr(0, limit);
chars = limit;
$('#t2').show();
}else{
$('#t2').hide();
}
elem.html( limit - chars );
}
setCount($(this)[0], elem);
}
});
})(jQuery);
//To setup the limiter, simply include a call similar to the one below:
var elem = $("#username");
$("#username").limiter(6, elem);
</script>
</body>
</html>
