Kriss Tan

Hi Paul,

I revisit the codes and tried some sample codes and found out certain things I would like to clarify with you.

Set<Map.Entry<Integer, Double>> entries = rank.entrySet(); List<Map.Entry<Integer, Double>> entryList = new ArrayList<Map.Entry<Integer, Double>>(entries); Collections.sort(entryList, (a comparator which you write to compare your Map.Entry objects)); Map<Integer, Double> gMap = new LinkedHashMap<Integer, Double>(); for (Map.Entry<Integer, Double> entry: entryList) { gMap.put(entry.getKey(), entry.getValue(); }

Why do we need to create a Set Map.Entry object to store the rank. entry set?

I tried it by just storing it in the arrayList and it still works...Any reason why you particularly store it in a Set?

List<Map.Entry<Integer, Double>> entryList = new ArrayList<Map.Entry<Integer, Double>>(rank.entrySet();

I changed to the above code written.

Looking forward to your reply.

Thanks!

Hey Paul,

I had spent some time reading through the API and tutorials but am unable to find a sample for comparing objects in Map.Entity.

Is it possible for you to provide me with some codes relating to comparing Map.Entity objects to work on with.

Thanks.

Hi Paul, thanks for replying.

Is it possible for you to briefly explain the codes?

What is Map.Entry? etc.. I am still learning more about hashmap in the process..

Thanks!

Hi, would appreciate if anyone can help me out on this.

I have a series of keys and values that I would like to add into a hashmap.

I am printing out the order using the values, only one key will be selected although I have got 3 keys. I am sure that this is the problem of the same values in my Arraylist. Can anyone suggest a solution for this?

What i need is that if it had taken out the 1st key then it will move on to retrieve the 2nd key and so on even though the values are the same.


keys values
1 0.0
2 0.0
3 0.0


List<Integer> mapKeys = new ArrayList<Integer>(rank.keySet()); //store all the keys listed above List<Double> mapValues = new ArrayList<Double>(rank.values()); //store all the values listed above List<Double> sortedMapValues = new ArrayList<Double>(rank.values()); //store all sorted values Collections.sort(sortedMapValues); System.out.println("Sorted Map Values" + sortedMapValues.toString()); Object[] sortedArray = sortedMapValues.toArray(); HashMap<Integer, Double> gMap = new LinkedHashMap<Integer, Double>(); int size = sortedArray.length; for(int i=0; i<size; i++) { gMap.put(mapKeys.get(mapValues.indexOf(sortedArray[i])), sortedArray[i].toString()); System.out.println("Order: " +gKeys.get(mapValues.indexOf(sortedArray[i])) + " " +sortedArray[i].toString()); System.out.println("KEYS " +gMap.keySet()); }