json转树状结构

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"}   ]‘);

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 jsonDataTree = transData(jsonData, ‘id‘, ‘pid‘, ‘chindren‘);