json转树状结构（js）

转自：http://rockyuse.iteye.com/blog/1541308

/**  * json格式转树状结构  * @param   {json}      json数据  * @param   {String}    id的字符串  * @param   {String}    父id的字符串  * @param   {String}    children的字符串  * @return  {Array}     数组  */  function transData(a, idStr, pidStr, chindrenStr){      var r = [], hash = {}, id = idStr, pid = pidStr, children = chindrenStr, i = 0, j = 0, len = a.length;      for(; i < len; i++){          hash[a[i][id]] = a[i];      }      for(; j < len; j++){          var aVal = a[j], hashVP = hash[aVal[pid]];          if(hashVP){              !hashVP[children] && (hashVP[children] = []);              hashVP[children].push(aVal);          }else{              r.push(aVal);          }      }      return r;  }    var jsonData = eval('[{"id":"4","pid":"1","name":"大家电"},{"id":"5","pid":"1","name":"生活电器"},{"id":"1","pid":"0","name":"家用电器"},{"id":"2","pid":"0","name":"服饰"},{"id":"3","pid":"0","name":"化妆"},{"id":"7","pid":"4","name":"空调"},{"id":"8","pid":"4","name":"冰箱"},{"id":"9","pid":"4","name":"洗衣机"},{"id":"10","pid":"4","name":"热水器"},{"id":"11","pid":"3","name":"面部护理"},{"id":"12","pid":"3","name":"口腔护理"},{"id":"13","pid":"2","name":"男装"},{"id":"14","pid":"2","name":"女装"},{"id":"15","pid":"7","name":"海尔空调"},{"id":"16","pid":"7","name":"美的空调"},{"id":"19","pid":"5","name":"加湿器"},{"id":"20","pid":"5","name":"电熨斗"}]');    var jsonDataTree = transData(jsonData, 'id', 'pid', 'chindren');  console.log(jsonDataTree);  //结果如下：[{"id":"1","pid":"0","name":"家用电器", "chindren":[{"id":"4","pid":"1","name":"大家电", "chindren":[{"id":"7","pid":"4","name":"空调", "chindren":[{"id":"15","pid":"7","name":"海尔空调"},{"id":"16","pid":"7","name":"美的空调"}]},{"id":"8","pid":"4","name":"冰箱"},{"id":"9","pid":"4","name":"洗衣机"},{"id":"10","pid":"4","name":"热水器"}]},{"id":"5","pid":"1","name":"生活电器","chindren":[{"id":"19","pid":"5","name":"加湿器"},{"id":"20","pid":"5","name":"电熨斗"}]}]},{"id":"2","pid":"0","name":"服饰","chindren":[{"id":"13","pid":"2","name":"男装"},{"id":"14","pid":"2","name":"女装"}]},{"id":"3","pid":"0","name":"化妆","chindren":[{"id":"11","pid":"3","name":"面部护理"},{"id":"12","pid":"3","name":"口腔护理"}]}]