javascript get object hierarchy keys #javascript

js get object hierarchy keys

input object :

{
  itemOne:{
    subItemOneOne:{},
    subItemOneTwo:{
      SubSubItemOneTwoOne:'ZEZEZEZEZEZEZE',
      SubSubItemOneTwoTwo:"kkokokokok"
    },
    subItemOneThree:['erererer', 'ffdfdfdf']
  },
  itemTwo:{
    subItemTwoOne:["popopopo","éopopopo"]
  }
}
output array of hierarchies :

[ 'itemOne.subItemOneOne.',
  'itemOne.subItemOneTwo.SubSubItemOneTwoOne',
  'itemOne.subItemOneTwo.SubSubItemOneTwoTwo',
  'itemOne.subItemOneThree',
  'itemTwo.subItemTwoOne' ]


/********************* recursice objects *************************************/

 function getStringOutOfHierarchy(obj){
    let finalString = [];
    let lastString = [];
    let stringHierarachy = recHierarchy(obj, Object.keys(obj))[0];

    finalString.map(elem => {
      if(elem.constructor === Array){
        elem.forEach(
          (subelem => {
            lastString.push(subelem);
          })
        );
      }
    });
    return lastString;
  
  
    function recHierarchy(obj, initial) {
      if(Object.keys(obj).length != 0){
        return Object.keys(obj).map((elem) => {
          let basString = elem;
          switch (typeof obj[elem]) {
          case 'string':{
            return [`${elem.toString()}`];
          }
          default :{
            return [`${elem.toString()}`];
          }
          case 'object':{
            if(obj[elem].constructor === Array ) {
              return  [`${elem.toString()}`];
            }
            let returnedValue = recHierarchy(obj[elem]);
            
            let recurMap = (mapElem) => {
                if(mapElem.constructor === Array) {
                    return mapElem.map(
                        (mapsubelem) => { 
                          if(mapsubelem.constructor === Array) { 
                            return recurMap(mapsubelem);
                          } 
                          return `${basString}.${mapsubelem.toString()}`;
                        }
                    );
                }
                return `${basString}.${mapElem.toString()}`;
            }

            let value = returnedValue.map(
              (elem) => {
                if(elem.constructor === Array) {
                  return elem.map(
                    (subelem) => {
                      if(elem.constructor === Array) {
                        return recurMap(subelem);
                     }
                      return `${basString}.${subelem.toString()}`;
                    }
                  );
                }  
                return `${basString}.${elem.toString()}`;
              }
            ); 
            (initial && initial.indexOf(elem) !== -1) ? finalString = finalString.concat(value) : null;
            return value;
          }
  
          }
        });
      }else{
        return [''];
      }
  
    }
  }