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adv.

jquery before()?? ???

??: before() ???? ??? ?? ?? ??? ??? ?????.

??: ??$(selector).before(content)

????:

ParametersDescription
content?????. ??? ???? ?????(HTML ?? ?? ??).

??? ???? ??? ??: ??? ???? ??? ?? ?? ???? ?????.

??: ??$(selector).before(function(index))

????:

???? Description
function(index) ?? . ??? ??? ???? ??? ?????.
index ????. ???? ??? ??? ????.

jquery before()?? ?

<html>
<head>
<script type="text/javascript" src="http://apps.bdimg.com/libs/jquery/2.1.1/jquery.min.js"></script>
<script type="text/javascript">
$(document).ready(function(){
  $(".btn1").click(function(){
    $("p").before("<p>Hello world!</p>");
  });
});
</script>
</head>
<body>
<p>This is a paragraph.</p>
<button class="btn1">在每個(gè)段落前面插入新的段落</button>
</body>
</html>
???? ?? ?

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