现有原数据

let arr = [
  {a:'age',b:18,c:1,...},
  {a:'age',b:19,c:1,...},
  {a:'age',b:18,c:2,...,
  {a:'sex',b:'m',.....}
  ....]

数据处理方法：

function arrObjToObjArr(arrObj,objKey,objValue){
      let Obj={}
       for(let i=0;i<arrObj.length;i++){
        for(let key in arrObj[i]){
          if(!(key in Obj)){
            Obj[objKey] = []
          }
          Obj[objKey].push(arrObj[i][objValue])
        }
      }
      return Obj
}
function repeatObjValueByKey(obj){//对象指定keys数组去重复
  for(let key in obj){
      obj[key] = _.uniqWith(Obj[key],_.Equal)//_为lodash引入别名
  }
  return obj
}

使用arrObjToObjArr

let obj = arrObjToObjArr(arr,'a','b')

获得obj

{
  age:[18,19,18],
  sex:['m']
}

使用repeatObjValueByKey

obj = repeatObjValueByKey(obj)

获得去重后的obj

{
  age:[18,19],
  sex:['m']
}