对象型数组按某个字段分类

   function groupByKey(list, key) {

            console.log(list);

            let tmpKeyList = list.map(o => o[key]);

            let keyList = [...new Set(tmpKeyList)];

            console.log(keyList); //一共有多少种分类

            let result = [];

            keyList.map(o => {

                let data = [];

                for (let i = 0, len = list.length; i < len; i++) {

                    if (list[i][key] == o) {

                        data.push(list[i].CNT);

                    }

                }

                result.push({

                    name: o,

                    data

                });

            });

            console.log(result);

        }

let list = [{

            APP_ID: "APP001",

            CNT: 0,

            STAT_DATE: "06-20"

        }, {

            APP_ID: "APP002",

            CNT: 0,

            STAT_DATE: "06-20"

        }, {

            APP_ID: "APP001",

            CNT: 0,

            STAT_DATE: "06-21"

        }, {

            APP_ID: "APP002",

            CNT: 0,

            STAT_DATE: "06-21"

        }];

groupByKey(list, 'APP_ID');