content: import java.util.Comparator;
  import java.util.SortedMap;
  import java.util.TreeMap;
  
  class TreeMap_Implementation {
  
  
      //A TreeMap is a map implementation where they are always sorted based on the natural ordering of the keys,
      // or based on a custom Comparator that you can provide at the time of creation of the TreeMap.
  
      //
          public static void main(String[] args) {
              // Creating a TreeMap
              SortedMap<String, String> names  = new TreeMap<>();
  
  
              // Adding new key-value pairs to a TreeMap
              names.put("Aanchal", "girl");
              names.put("Rahul", "boy");
              names.put("Arjun", "boy");
              names.put("Karen", "girl");
              names.put("Salman", "boy");
  
              // Printing the TreeMap (Output will be sorted based on keys)
              System.out.println(names);
  
              System.out.println(((TreeMap<String, String>) names).firstEntry());
  
              System.out.print(((TreeMap<String, String>) names).lastEntry());
  
  
              SortedMap<String, String> names_2 = new TreeMap<>(new Comparator<String>() {
                  @Override
                  public int compare(String s1, String s2) {
                      return s2.compareTo(s1);
                  }
              });
  
              // Adding new key-value pairs to a TreeMap
              names_2.put("Aanchal", "girl");
              names_2.put("Rahul", "boy");
              names_2.put("Arjun", "boy");
              names_2.put("Karen", "girl");
              names_2.put("Salman", "boy");
  
              // Printing the TreeMap (The keys will be sorted based on the supplied comparator in descending order.)
              System.out.println(names_2);
  
              System.out.println(((TreeMap<String, String>) names_2).firstEntry());
  
              System.out.print(((TreeMap<String, String>) names_2).lastEntry());
          }
  
      }
  
  
     /* Output:
              {Aanchal=girl, Arjun=boy, Karen=girl, Rahul=boy, Salman=boy}
              Aanchal=girl
              Salman=boy{Salman=boy, Rahul=boy, Karen=girl, Arjun=boy, Aanchal=girl}
              Salman=boy
              Aanchal=girl*/
  