html
<div class="words" <textarea id="textID" placeholder="请输入您的中秋节祝福"></textarea> <samp>还可以输入<span>50</span>个字</samp> </div>
js
var lens=0; $(".words textarea").bind('input propertychange',function(){ lens=get_length($(this).val()); var lastStr = parseInt(50-lens); console.log(lens,lastStr); if(lastStr<=0){ lastStr=0 } $(".words samp").html("还可以输入<span>"+lastStr+"</span>个字"); });