map遍历数组返回包含所需字段的对象

假如dataList为后台假数据，我想分别得到number和chargeTime、number和freeTime，来分别画图，就可以这么写，当然直接for循环更可以。

 1 const dataList = {
 2     list:[
 3         {
 4             number: "0",
 5             chargeTime: 2,
 6             freeTime: 5
 7         },{
 8             Number: "1",
 9             chargeTime: 8,
10             freeTime: 9
11         },
12         ......
13       ]};        
14 
15  const chargeTimeAndNumber = dataList.list.map(item => ({
16     number:item.number,
17     chargeTime:item.chargeTime
18 }));
19  const freeTimeAndNumber = dataList.list.map(item => ({
20     number:item.number,
21     freeTime:item.freeTime
22 }));