[{"_id":"6225ca4052e7c226e2dd836d","data":["58","42","12","19","47","32","99","57","71","81","32","97","52","32","58","92"]}]

db.collection.aggregate([{$set:{data:{$function:{body:"function(d) {let obj = {}; d.forEach(e => {if(obj[e]==null) { obj[e]=1; }else{ obj[e]++; }}); return obj;}",args:["$data"],lang:"js"}}}}])