js implementation code to delete duplicate items in select_form effects

<meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <title>Delete duplicate items in select</title> <style type="text/css"> body{ text-align:center;} div{ width:400px; background:#f1f5fa; margin:auto; border:solid 1px #BFC9DB; padding:10px;} h4{ } a{text-align:right; display:block; font-size:12px;} </style> <div> <h4> </h4>Demo of selecting duplicate items<a href="http://www.jb51.net/" target="_blank" title="http://www.jb51.net/"> </a>http://www.jb51.net/<hr> <select id="sel" multiple size="1"> <option></option></select>To be initialized...<hr> <button id="btnInital"> </button>Initialization<button id="btnDistinct"> </button>Remove duplicates</div>
[Ctrl A select all Note: If you need to introduce external Js, you need to refresh to execute

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Effect

Source: 51obj