我有这样的JSON:[{platformId:1,payout:15,numOfPeople:4},{platformId:1,payout:12,numOfPeople:3},{platformId:2,payout:6,numOfPeople:5},{platformId:2,payout:10,numOfPeople:1},]我想按platformId以及payout和numOfPeople的总和对其进行分组。即结果我想要这样的JSON:["1":{payout:27,numOfPeople:7},"2":{payout:16,numOfPeople:6}]我尝试使用unders