SortedMap

Introduction to sorted Map.

Introduction to sorted Map.

Keypoint :-

• SortedMap interface extends Map.
• entries are maintained in an ascending key order.

Methods of sorted Map :

• Comparator comparator( ).
• Object firstKey( ).
• SortedMap headMap(Object end).
• Object lastKey( ).
• SortedMap subMap(Object start, Object end).
• SortedMap tailMap(Object start).

Example

public static void main(String args[]) {
      // Create a hash map
      TreeMap tm = new TreeMap();

      // Put elements to the map
      tm.put("Zara", new Double(3434.34));
      tm.put("Mahnaz", new Double(123.22));
      tm.put("Ayan", new Double(1378.00));
      tm.put("Daisy", new Double(99.22));
      tm.put("Qadir", new Double(-19.08));

      // Get a set of the entries
      Set set = tm.entrySet();

      // Get an iterator
      Iterator i = set.iterator();

      // Display elements
      while(i.hasNext()) {
         Map.Entry me = (Map.Entry)i.next();
         System.out.print(me.getKey() + ": ");
         System.out.println(me.getValue());
      }
      System.out.println();

      // Deposit 1000 into Zara's account
      double balance = ((Double)tm.get("Zara")).doubleValue();
      tm.put("Zara", new Double(balance + 1000));
      System.out.println("Zara's new balance: " + tm.get("Zara"));
   }