代码示例:(标识:jquery_dim_width_height_set)
<!DOCTYPE html>
<html>
<head>
<script src="/jquery/jquery-1.11.1.min.js"></script>
<script>
$(document).ready(function(){
  $("button").click(function(){
    $("#div1").width(320).height(320);
  });
});
</script>
</head>
<body>

<div id="div1" style="height:100px;width:300px;padding:10px;margin:3px;border:1px solid blue;background-color:lightblue;"></div>
<br>
<button>调整 div 的尺寸</button>

</body>
</html>
运行结果: