/*
 ### jQuery XML to JSON Plugin v1.2 - 2013-02-18 ###
 * http://www.fyneworks.com/ - diego@fyneworks.com
	* Licensed under http://en.wikipedia.org/wiki/MIT_License
 ###
 Website: http://www.fyneworks.com/jquery/xml-to-json/
*//*
 # INSPIRED BY: http://www.terracoder.com/
           AND: http://www.thomasfrank.se/xml_to_json.html
											AND: http://www.kawa.net/works/js/xml/objtree-e.html
*//*
 This simple script converts XML (document of code) into a JSON object. It is the combination of 2
 'xml to json' great parsers (see below) which allows for both 'simple' and 'extended' parsing modes.
*/
// Avoid collisions
;if(window.jQuery) (function($){
 
 // Add function to jQuery namespace
 $.extend({
  
  // converts xml documents and xml text to json object
  xml2json: function(xml, extended) {
   if(!xml) return {}; // quick fail
   
   //### PARSER LIBRARY
   // Core function
   function parseXML(node, simple){
    if(!node) return null;
    var txt = '', obj = null, att = null;
    var nt = node.nodeType, nn = jsVar(node.localName || node.nodeName);
    var nv = node.text || node.nodeValue || '';
    /*DBG*/ //if(window.console) console.log(['x2j',nn,nt,nv.length+' bytes']);
    if(node.childNodes){
     if(node.childNodes.length>0){
      /*DBG*/ //if(window.console) console.log(['x2j',nn,'CHILDREN',node.childNodes]);
      $.each(node.childNodes, function(n,cn){
       var cnt = cn.nodeType, cnn = jsVar(cn.localName || cn.nodeName);
       var cnv = cn.text || cn.nodeValue || '';
       /*DBG*/ //if(window.console) console.log(['x2j',nn,'node>a',cnn,cnt,cnv]);
       if(cnt == 8){
        /*DBG*/ //if(window.console) console.log(['x2j',nn,'node>b',cnn,'COMMENT (ignore)']);
        return; // ignore comment node
       }
       else if(cnt == 3 || cnt == 4 || !cnn){
        // ignore white-space in between tags
        if(cnv.match(/^\s+$/)){
         /*DBG*/ //if(window.console) console.log(['x2j',nn,'node>c',cnn,'WHITE-SPACE (ignore)']);
         return;
        };
        /*DBG*/ //if(window.console) console.log(['x2j',nn,'node>d',cnn,'TEXT']);
        txt += cnv.replace(/^\s+/,'').replace(/\s+$/,'');
								// make sure we ditch trailing spaces from markup
       }
       else{
        /*DBG*/ //if(window.console) console.log(['x2j',nn,'node>e',cnn,'OBJECT']);
        obj = obj || {};
        if(obj[cnn]){
         /*DBG*/ //if(window.console) console.log(['x2j',nn,'node>f',cnn,'ARRAY']);
         
									// http://forum.jquery.com/topic/jquery-jquery-xml2json-problems-when-siblings-of-the-same-tagname-only-have-a-textnode-as-a-child
									if(!obj[cnn].length) obj[cnn] = myArr(obj[cnn]);
									obj[cnn] = myArr(obj[cnn]);
         
									obj[cnn][ obj[cnn].length ] = parseXML(cn, true/* simple */);
         obj[cnn].length = obj[cnn].length;
        }
        else{
         /*DBG*/ //if(window.console) console.log(['x2j',nn,'node>g',cnn,'dig deeper...']);
         obj[cnn] = parseXML(cn);
        };
       };
      });
     };//node.childNodes.length>0
    };//node.childNodes
    if(node.attributes){
     if(node.attributes.length>0){
      /*DBG*/ //if(window.console) console.log(['x2j',nn,'ATTRIBUTES',node.attributes])
      att = {}; obj = obj || {};
      $.each(node.attributes, function(a,at){
       var atn = jsVar(at.name), atv = at.value;
       att[atn] = atv;
       if(obj[atn]){
        /*DBG*/ //if(window.console) console.log(['x2j',nn,'attr>',atn,'ARRAY']);
        
								// http://forum.jquery.com/topic/jquery-jquery-xml2json-problems-when-siblings-of-the-same-tagname-only-have-a-textnode-as-a-child
								//if(!obj[atn].length) obj[atn] = myArr(obj[atn]);//[ obj[ atn ] ];
        obj[cnn] = myArr(obj[cnn]);
								
								obj[atn][ obj[atn].length ] = atv;
        obj[atn].length = obj[atn].length;
       }
       else{
        /*DBG*/ //if(window.console) console.log(['x2j',nn,'attr>',atn,'TEXT']);
        obj[atn] = atv;
       };
      });
      //obj['attributes'] = att;
     };//node.attributes.length>0
    };//node.attributes
    if(obj){
     obj = $.extend( (txt!='' ? new String(txt) : {}),/* {text:txt},*/ obj || {}/*, att || {}*/);
     txt = (obj.text) ? (typeof(obj.text)=='object' ? obj.text : [obj.text || '']).concat([txt]) : txt;
     if(txt) obj.text = txt;
     txt = '';
    };
    var out = obj || txt;
    //console.log([extended, simple, out]);
    if(extended){
     if(txt) out = {};//new String(out);
     txt = out.text || txt || '';
     if(txt) out.text = txt;
     if(!simple) out = myArr(out);
    };
    return out;
   };// parseXML
   // Core Function End
   // Utility functions
   var jsVar = function(s){ return String(s || '').replace(/-/g,"_"); };
   
			// NEW isNum function: 01/09/2010
			// Thanks to Emile Grau, GigaTecnologies S.L., www.gigatransfer.com, www.mygigamail.com
			function isNum(s){
				// based on utility function isNum from xml2json plugin (http://www.fyneworks.com/ - diego@fyneworks.com)
				// few bugs corrected from original function :
				// - syntax error : regexp.test(string) instead of string.test(reg)
				// - regexp modified to accept  comma as decimal mark (latin syntax : 25,24 )
				// - regexp modified to reject if no number before decimal mark  : ".7" is not accepted
				// - string is "trimmed", allowing to accept space at the beginning and end of string
				var regexp=/^((-)?([0-9]+)(([\.\,]{0,1})([0-9]+))?$)/
				return (typeof s == "number") || regexp.test(String((s && typeof s == "string") ? jQuery.trim(s) : ''));
			};
			// OLD isNum function: (for reference only)
			//var isNum = function(s){ return (typeof s == "number") || String((s && typeof s == "string") ? s : '').test(/^((-)?([0-9]*)((\.{0,1})([0-9]+))?$)/); };
																
   var myArr = function(o){
    
				// http://forum.jquery.com/topic/jquery-jquery-xml2json-problems-when-siblings-of-the-same-tagname-only-have-a-textnode-as-a-child
				//if(!o.length) o = [ o ]; o.length=o.length;
    if(!$.isArray(o)) o = [ o ]; o.length=o.length;
				
				// here is where you can attach additional functionality, such as searching and sorting...
    return o;
   };
   // Utility functions End
   //### PARSER LIBRARY END
   
   // Convert plain text to xml
   if(typeof xml=='string') xml = $.text2xml(xml);
   
   // Quick fail if not xml (or if this is a node)
   if(!xml.nodeType) return;
   if(xml.nodeType == 3 || xml.nodeType == 4) return xml.nodeValue;
   
   // Find xml root node
   var root = (xml.nodeType == 9) ? xml.documentElement : xml;
   
   // Convert xml to json
   var out = parseXML(root, true /* simple */);
   
   // Clean-up memory
   xml = null; root = null;
   
   // Send output
   return out;
  },
  
  // Convert text to XML DOM
  text2xml: function(str) {
   // NOTE: I'd like to use jQuery for this, but jQuery makes all tags uppercase
   //return $(xml)[0];
   var out;
   try{
    var xml = ((!$.support.opacity && !$.support.style))?new ActiveXObject("Microsoft.XMLDOM"):new DOMParser();
    xml.async = false;
   }catch(e){ throw new Error("XML Parser could not be instantiated") };
   try{
    if((!$.support.opacity && !$.support.style)) out = (xml.loadXML(str))?xml:false;
    else out = xml.parseFromString(str, "text/xml");
   }catch(e){ throw new Error("Error parsing XML string") };
   return out;
  }
		
 }); // extend $

})(jQuery);

别人写的，需要用到jQuery库，用法$.xml2json()

javascript xml字符串转为JSON对象