Trying to put classes in hashmap but its not working

Question

So i have input like this:

 [1]     name1 + type1 + value1
 [X]     nameX + typeX + valueX

now i am looking at input like this:

 [2]     name1 + type2 + value2

so [2] has same name as [1] but their properites are different.

i put the name,type,value in a class like this:

 class entity(){

 String name;
 String type;
 int amount;
 //constructor ... etc...
 ...
 }

what i want to do is put entity into a hashmap with the key being the name and the value being the class entity.

like this

  name1 ----> entity1
  nameX -----> entityX

the problem i am having is when i try to put [2] into the hashmap it has the same name as [1] so it doesnt hash properly ([2] overrides [1] since they have the same name.

i will need to later access [1] and [2] by their name when i search for it.. how would i enter it into the map so it wont override it.

@NafisIslam what would you suggest to use? i will need to search up the class using the name? — user12015793, Oct 09 '19 at 17:41
If [1] and [2] have the same name how do you distinguish this 2? — Nafis Islam, Oct 09 '19 at 17:45

score 0 · Accepted Answer · answered Oct 09 '19 at 17:46

0

1 - You need to modify your class entity like below :-

 class entity(){

 String name;
 ArrayList <String> type;
 ArrayList <Integer> amount;
 //constructor ... etc...
 ...
 }

2 - Now when ever you are going to enter any value in hashmap, First check that is that key is available in map. If key is available in map, fetch that value associated to that key and enter your new type and amount value in arraylist.

if(hashmap.contains(nameX)){
    entity obj = hashmap.get(nameX);
    type.add(new_val);
    amount.add(new_val);
    hashmap.put(nameX,obj);
}
else{
    entity obj = new entity();
    type.add(new_val);
    amount.add(new_val);
    hashmap.put(nameX,obj);
}

Note:- change your class name from entity to Entity. its standards code pratice.

answered Oct 09 '19 at 17:46

SSP

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for any question comment here – SSP Oct 09 '19 at 17:49
ill try this and see if it works in my code... that entity was just a simple explanation of my problem so i wrote it on the spot – user12015793 Oct 09 '19 at 17:51
that's all right. I just wanted you to know that, its not the correct way to write a class name. – SSP Oct 09 '19 at 17:53
just finished my looong program and this worked... thank you. – user12015793 Oct 09 '19 at 19:27

Trying to put classes in hashmap but its not working

1 Answers1