学步园

      var DOCTYPE = "",doctype;
      if((doctype = document.doctype)) {
        DOCTYPE += '<!DOCTYPE ' + doctype.name +(doctype.publicId ? (' '+doctype.publicId+ ' "' + doctype.systemId + '">')  :'>')
      }else if((doctype = document.getElementsByTagName("!")[0])){
        DOCTYPE = doctype.text;
      }
      alert(DOCTYPE);

<br /> var DOCTYPE = "",doctype;<br /> if((doctype = document.doctype)) {<br /> DOCTYPE += ' + doctype.name +(doctype.publicId ? (' '+doctype.publicId+ ' "' + doctype.systemId + '">') :'>')<br /> }else if((doctype = document.getElementsByTagName("!")[0])){<br /> DOCTYPE = doctype.text;<br /> }<br /> alert(DOCTYPE);<br />

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