Working of TreeMap in Java has been added

Author: Aanchal.Sharma

data-structures/TreeMap_Implementation.java

@@ -0,0 +1,62 @@
+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*/