<script src="/js/jquery-1.11.1.min.js"></script>
$(document).ready(function(){
$("#btn1").click(function(){
$("#test1").text(function(i,origText){
return "Old text: " + origText + " New text: Hello world! (index: " + i + ")";
$("#btn2").click(function(){
$("#test2").html(function(i,origText){
return "Old html: " + origText + " New html: Hello <b>world!</b> (index: " + i + ")";
<p id="test1">这是<b>粗体</b>文本。</p>
<p id="test2">这是另一段<b>粗体</b>文本。</p>
<button id="btn1">显示旧/新文本</button>
<button id="btn2">显示旧/新 HTML</button>