add arrayList into HashMap with looping [kotlin code]

Question

I'm trying to put the itemList as array which is fetching from other function, and put it into Hash Map. After the loop finished, I try to print the content which is wrong.

class ExpandableItemClass : AppCompatActivity() {
    private var expandableListAdapter: ExpandableListViewAdapter? = null
    private lateinit var titleList : List<String>   
    private lateinit var myHasMap: HashMap<String, List<String>>  
    private var itemList : ArrayList<String> ? = null


    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_pobitrota)

        titleList = ArrayList()
        myHasMap = HashMap()
        itemList = ArrayList()


        getAllTitles()

        expandableListAdapter = ExpandableListViewAdapter(this@PobitrotaActivity, titleList, myHasMap)
        pobitrota_recyclerListView.setAdapter(expandableListAdapter)


    }



    private fun getAllTitles() {
        var pRef = FirebaseDatabase.getInstance().reference.child("Titles")
        pRef.addValueEventListener(object : ValueEventListener{
            override fun onCancelled(error: DatabaseError) {

            }
            override fun onDataChange(snapshot: DataSnapshot) {
                if(snapshot.exists()){
                    (chapterList as ArrayList<String>).clear()
                    for (item in snapshot.children){
                        var subItem = item.getValue(Title::class.java)
                        if(subItem!!.getMainTitleId().equals("-M_FyZJbyXf3fLFyEuiT")){
                            (titleList as ArrayList<String>).add(subItem.getTitleName())

                            getAllItems(item.key!!)
                        }
                    }
                    
                }
            }
        })
    }


    private fun getAllItems(titleId: String) {
        var pRef = FirebaseDatabase.getInstance().reference.child("DropdownItems")
        pRef.addValueEventListener(object : ValueEventListener{
            override fun onCancelled(error: DatabaseError) {

            }
            override fun onDataChange(snapshot: DataSnapshot) {
                if(snapshot.exists()){
                    dropdownList!!.clear()
                    for (item in snapshot.children){
                        var stdItem = item.getValue(Item::class.java)
                        if(stdItem!!.getTitleId().equals(titleId)){
                            itemList!!.add(stdItem.getItemName())
                        }
                    }

                    while(index < titleList.size){
                        myHasMap.put(titleList[index], itemList!!)

                        break
                    }
                    index = index + 1


                    for(key in myHasMap.keys){
                        Log.d("TAG", key+" => "+myHasMap[key])
                    }

                    expandableListAdapter!!.notifyDataSetChanged()
                }
            }

        })
    }


}

Here is the result like below:

//1st iterator:
title1 => [item1, item2, item3]

//2nd iterator:
title1 => [item4, item5]
title2 => [item4, item5]


//3rd iterator:
title1 => [item6, item7]
title2 => [item6, item7]
title3 => [item6, item7]

Here is the result and it is correct. I hope so:

//1st iterator:
title1 => [item1, item2, item3]

//2nd iterator:
title1 => [item1, item2, item3]
title2 => [item4, item5]


//3rd iterator:
title1 => [item1, item2, item3]
title2 => [item4, item5]
title3 => [item6, item7]

I am guessing my problem is that hasmap can't save the data added to the hasmap.

What is the correct way to add data into hashmap? How can I get the right results?

Answer 1

Here is example how you can add an arrayList in other array of bundle

 val items = eventData.get(EVENT_PARAM_CART_ITEM) as ArrayList<Item>
 var arrayOf = arrayListOf<Bundle>()

 for ((index, item) in items.withIndex()) {
           
            val itemJeggings = Bundle().apply {
                putString(FirebaseAnalytics.Param.ITEM_ID, items[index].itemId.toString())
                putString(FirebaseAnalytics.Param.ITEM_BRAND, items[index].brand)
                putLong(FirebaseAnalytics.Param.QUANTITY, items[index].quantity?.toLong()!!)
                putString(FirebaseAnalytics.Param.CURRENCY, items[index].currency)
                putDouble(FirebaseAnalytics.Param.PRICE, items[index].price?.toDouble()!!)
            }
            arrayOf.add(itemJeggings)
        }