<!DOCTYPE html>
<html>
<head>
<script src="/jquery/jquery-1.8.3.min.js"></script>
<script>
$(document).ready(function(){
  $("#btn1").click(function(){
    $("img").before("<b>Before</b>");
  });

  $("#btn2").click(function(){
    $("img").after("<i>After</i>");
  });
});
</script>
</head>

<body>
<img src="/i/eg_W3Schools.gif" alt="W3Schools Logo" />
<br><br>
<button id="btn1">在图片前面添加文本</button>
<button id="btn2">在图片后面添加文本</button>
</body>
</html>