W3School TIY Editor
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<html> <head> <script type="text/javascript" src="/jquery/jquery.js"></script> <script type="text/javascript"> $(document).ready(function(){ $("button").click(function(){ $("p").before(function(n){ return "<p>The p element below has index " + n + "</p>"; }); }); }); </script> </head> <body> <h1>This is a heading</h1> <p>This is a paragraph.</p> <p>This is another paragraph.</p> <button class="btn1">在每个段落前面插入新的段落</button> </body> </html>