CODEWITHSUNDEEP
javahashmapprocessing
Javacadabra
Javacadabra

Reputation: 5768

Storing Data in a HashMap Java

I am trying to store data in a HashMap however I can only seem to store the very last item of the data source I am reading into the HashMap and I am unsure why.

Below is my code:

//Loops through the counties and stores the details in a Hashmap
void getCountyDetails(List<Marker>m){  
   HashMap t = new HashMap();
  for(Marker county: countyMarkers){
    println("county:" + county.getProperties());
     t = county.getProperties();
  }
  println(t);
}

This line -> println("county:" + county.getProperties());

Outputs this:

county:{name=Carlow, pop=54,612}
county:{name=Cavan, pop=73,183}
county:{name=Clare, pop=117,196}
county:{name=Cork, pop=519,032}
county:{name=Donegal, pop=161,137}
county:{name=Dublin, pop=1,273,069}
county:{name=Galway, pop=250,541}
county:{name=Kerry, pop=145,502}
county:{name=Kildare, pop=210,312}
county:{name=Kilkenny, pop=95,419}
county:{name=Laois, pop=80,559}
county:{name=Letrim, pop=31,796}
county:{name=Limerick, pop=191,809}
county:{name=Longford, pop=39,000}
county:{name=Louth, pop=122,897}
county:{name=Mayo, pop=130,638}
county:{name=Meath, pop=184,135}
county:{name=Monaghan, pop=60,483}
county:{name=Offaly, pop=76,687}
county:{name=Roscommon, pop=64,065}
county:{name=Sligo, pop=65,393}
county:{name=Tipperary, pop=158,754}
county:{name=Waterford, pop=113,795}
county:{name=Westmeath, pop=86,164}
county:{name=Wexford, pop=145,320}
county:{name=Wicklow, pop=136,640}

I would like to store them in a HashMap.

This line -> println(t); outputs:

{name=Wicklow, pop=136,640}

Would appreciate any help on the matter guys. Basically it's just getting the list of data into the hashmap and currently only the last item in that list is being placed in.

Upvotes: 0

Views: 1085

Answers (2)

Svetlin Zarev
Svetlin Zarev

Reputation: 15713

If you want to print the properties of each Marker , move the println(t) line into the for loop, because at the moment t will point to the last used element's properties, because you just reassign it;s value each iteration of the cycle. To put an element in the map, use put(Key, Value) or putAll() methods instead

Upvotes: 3

weiyueli
weiyueli

Reputation: 31

In java, you should use hashMap.put(key, value) to add new item into hash map. In your code, you wrote HashMap t = new HashMap(); t = county.getProperties(); so you map value is actually been reassigned to country property each time.

Upvotes: 0

Related Questions