05 - json转成树状结构

       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(data, idStr, pidStr, chindrenStr) {
         var arr = [],
           hash = {},
           id = idStr,
           pid = pidStr,
           children = chindrenStr;
 
         for (var i = 0; i < data.length; i++) {
           hash[data[i][id]] = data[i];
         }
         for (var j = 0; j < data.length; j++) {
           //data 中每一项
           var arrVal = data[j],
             //找父分类
             hashVP = hash[arrVal[pid]];
           //pid 不为 0
           if (hashVP) {
             !hashVP[children] && (hashVP[children] = []);
             hashVP[children].push(arrVal);
           }
           //pid 为 0
           else {
             // 将data 的对象添加到数组中
             arr.push(arrVal);
           }
         }
         return arr;
       }
 
       var jsonDataTree = transData(jsonData, 'id', 'pid', 'chindren');
       console.log(jsonDataTree);