diff --git a/src/main/java/com/demo/program/collection/ArrayListDemo.java b/src/main/java/com/demo/program/collection/ArrayListDemo.java
new file mode 100644
index 0000000..ddaaaf7
--- /dev/null
+++ b/src/main/java/com/demo/program/collection/ArrayListDemo.java
@@ -0,0 +1,36 @@
+package com.collection;
+
+import java.util.ArrayList;
+
+public class ArrayListDemo {
+	
+	public static void main(String[] args) {
+		
+		ArrayList list = new ArrayList();
+		list.add(new Integer(10));
+		list.add(new Float(20.6));
+		list.add(new String("ABC"));
+		list.add("Welcome");
+		list.add(30.8);
+		list.add(1, "HI");
+		list.add(30.8);
+		list.add(new Employee(10,"Sakshi",10.5f));
+		list.add(new Employee(12,"Palak",13.5f));
+		for(int i=0;i<list.size();i++)
+		{
+			Object obj = list.get(i);
+			if(obj instanceof Employee){
+				System.out.println("Employee Details:");
+				System.out.println("Id: "+((Employee)obj).getId());
+				System.out.println("Name: "+((Employee)obj).getName());
+				System.out.println("Salary: "+((Employee)obj).getSalary());
+			}
+			else
+			{
+			     System.out.println(obj);
+			}
+		}
+		
+	}
+
+}
diff --git a/src/main/java/com/demo/program/collection/Employee.java b/src/main/java/com/demo/program/collection/Employee.java
new file mode 100644
index 0000000..6f1999b
--- /dev/null
+++ b/src/main/java/com/demo/program/collection/Employee.java
@@ -0,0 +1,51 @@
+package com.collection;
+
+public class Employee {
+
+	private int id;
+	private String name;
+	private float salary;
+	
+	public Employee(int id, String name, float salary) {
+		this.id = id;
+		this.name = name;
+		this.salary = salary;
+	}
+
+	public int getId() {
+		return id;
+	}
+
+	public String getName() {
+		return name;
+	}
+
+	public float getSalary() {
+		return salary;
+	}
+	
+	public String toString()
+	{
+		return ("ID:"+id+" Name:"+name+" Salary:"+salary);
+	}
+	
+	public int hashCode()
+	{
+		return id;
+	}
+	
+	public boolean equals(Object obj)
+	{
+		if(obj instanceof Employee)
+		{
+		  Employee e = (Employee)obj;
+		  if(this.id==e.id && this.name==e.name && this.salary==e.salary)
+		  {
+			return true;
+		  }
+		}
+	return false;
+		
+	}
+	
+}
diff --git a/src/main/java/com/demo/program/collection/HashSetDemo.java b/src/main/java/com/demo/program/collection/HashSetDemo.java
new file mode 100644
index 0000000..2dadadf
--- /dev/null
+++ b/src/main/java/com/demo/program/collection/HashSetDemo.java
@@ -0,0 +1,30 @@
+package com.collection;
+
+import java.util.HashSet;
+import java.util.Iterator;
+
+public class HashSetDemo {
+
+	public static void main(String[] args) {
+		
+		HashSet h = new HashSet();
+		
+		h.add(new Integer(100));
+		h.add(10.9);
+		h.add(60.5f);
+	  	h.add("Hello World!");
+		h.add(60.5f);
+		h.add(new Employee(10,"Sakshi",100000));
+		h.add(new Employee(12,"Palak",100000));
+		h.add(new Employee(10,"Ritesh",100000));
+		h.add(new Employee(12,"Prachi",100000));
+		h.add(10);
+	    Iterator i = h.iterator();
+			
+		while(i.hasNext())
+		{
+			Object o = i.next();
+			System.out.println(o);
+		}
+	}
+}
diff --git a/src/main/java/com/demo/program/collection/Product.java b/src/main/java/com/demo/program/collection/Product.java
new file mode 100644
index 0000000..e6c5858
--- /dev/null
+++ b/src/main/java/com/demo/program/collection/Product.java
@@ -0,0 +1,48 @@
+package com.collection;
+
+public class Product implements Comparable<Product>{
+
+	private int productId;
+	private String productName;
+	private float price;
+	public Product(int productId, String productName, float price) {
+		super();
+		this.productId = productId;
+		this.productName = productName;
+		this.price = price;
+	}
+
+	public int getProductId() {
+		return productId;
+	}
+
+	public String getProductName() {
+		return productName;
+	}
+
+	public float getPrice() {
+		return price;
+	}
+
+	public String toString() {
+		return "Product [productId=" + productId + ", productName="
+				+ productName + ", price=" + price + "]";
+	}
+	
+	/*public int compareTo(Object obj)
+	{
+        Product p = (Product)obj;
+		if(this.productId>(p.productId)){
+			return 1;
+		}
+		else if(this.productId<p.productId){
+			return -1;
+		}
+		return 0;*/
+		
+	public int compareTo(Product p)
+	{
+		return p.productId - this.productId;	
+		//return this.productId - p.productId;	
+	}
+}
diff --git a/src/main/java/com/demo/program/collection/ProductCompare.java b/src/main/java/com/demo/program/collection/ProductCompare.java
new file mode 100644
index 0000000..1f10abc
--- /dev/null
+++ b/src/main/java/com/demo/program/collection/ProductCompare.java
@@ -0,0 +1,17 @@
+package com.collection;
+
+import java.util.Comparator;
+
+public class ProductCompare implements Comparator<Product>{
+	
+	/*public int compare(Object obj1, Object obj2) {
+		
+		Product p1 = (Product)obj1;
+		Product p2 = (Product)obj2;
+		return p1.getProductName().compareTo(p2.getProductName());
+	}
+*/
+	public int compare(Product obj1, Product obj2) {
+	return obj1.getProductName().compareTo(obj2.getProductName());
+} 
+}
diff --git a/src/main/java/com/demo/program/collection/TreeSetDemo.java b/src/main/java/com/demo/program/collection/TreeSetDemo.java
new file mode 100644
index 0000000..c315cf6
--- /dev/null
+++ b/src/main/java/com/demo/program/collection/TreeSetDemo.java
@@ -0,0 +1,61 @@
+package com.collection;
+
+import java.util.Iterator;
+import java.util.TreeSet;
+
+public class TreeSetDemo {
+
+	public static void main(String[] args) {
+		
+		TreeSet<Integer> t = new TreeSet<Integer>();
+		
+		t.add(new Integer(10));
+		t.add(20);
+		t.add(30);
+		t.add(100);
+		t.add(100);
+		t.add(100);
+		
+		Iterator<Integer> it = t.iterator();
+		while(it.hasNext())
+		{
+			Object o = it.next();
+			System.out.println(o);
+		}
+		
+TreeSet<String> ts = new TreeSet<String>();
+		
+		ts.add("Hi");
+		ts.add("Hello");
+		ts.add("Welcome");
+		ts.add("Good Morning");
+		
+		System.out.println(ts);
+		
+		TreeSet<Product> p =  new TreeSet<Product>();
+        p.add(new Product(11, "Shoes", 1000));
+        p.add(new Product(13, "Watches",3460));
+        p.add(new Product(12, "Bags", 4000));
+     
+        
+        Iterator<Product> it1 = p.iterator(); 
+        while(it1.hasNext())
+        {
+        	Product p1 = it1.next();
+        	System.out.println(p1);
+        }
+        System.out.println("----------------------------------------------------");
+        TreeSet<Product> p1 =  new TreeSet<Product>(new ProductCompare());
+        p1.add(new Product(11, "Shoes", 1000));
+        p1.add(new Product(13, "Watches",3460));
+        p1.add(new Product(12, "Bags", 4000));
+     
+        
+        Iterator<Product> it2 = p1.iterator(); 
+        while(it2.hasNext())
+        {
+        	Product p2 = it2.next();
+        	System.out.println(p2);
+        }
+	}
+}
diff --git a/src/main/java/com/demo/program/collection/VectorDemo.java b/src/main/java/com/demo/program/collection/VectorDemo.java
new file mode 100644
index 0000000..e4687c8
--- /dev/null
+++ b/src/main/java/com/demo/program/collection/VectorDemo.java
@@ -0,0 +1,29 @@
+package com.collection;
+
+import java.util.Enumeration;
+import java.util.Vector;
+
+public class VectorDemo {
+	
+	public static void main(String[] args) {
+		
+		Vector list = new Vector();
+		
+		list.addElement(new Integer(20));
+		list.addElement(20.5f);
+		list.addElement(30);
+		list.addElement("Hello");
+		list.addElement(new String("Hi"));
+		list.addElement(new String("Hi"));
+		list.add(new Employee(10,"Sakshi",10.5f));
+		list.add(new Employee(12,"Palak",13.5f));
+		Enumeration e = list.elements();
+		while(e.hasMoreElements())
+		{
+			Object o = e.nextElement();
+			System.out.println(o);
+		}
+		
+	}
+
+}
diff --git a/src/main/java/com/demo/program/mapdemo/Employee.java b/src/main/java/com/demo/program/mapdemo/Employee.java
new file mode 100644
index 0000000..bcb1d8b
--- /dev/null
+++ b/src/main/java/com/demo/program/mapdemo/Employee.java
@@ -0,0 +1,37 @@
+package com.map;
+
+public class Employee {
+	
+	private int id;
+	private String name;
+	private float salary;
+	public Employee(int id, String name, float salary) {
+		super();
+		this.id = id;
+		this.name = name;
+		this.salary = salary;
+	}
+	@Override
+	public String toString() {
+		return "Employee [id=" + id + ", name=" + name + ", salary=" + salary
+				+ "]";
+	}
+	
+	public int hashCode()
+	{
+		return id;	
+	}
+	
+    public boolean equals(Object obj)
+    {
+    	Employee emp = (Employee)obj;
+    	if(this.name.equals(emp.name))
+    	{
+    		if(this.salary == emp.salary)
+    		{
+    			return true;
+    		}
+    	}
+        return false;
+    }
+}
diff --git a/src/main/java/com/demo/program/mapdemo/HashMapDemo.java b/src/main/java/com/demo/program/mapdemo/HashMapDemo.java
new file mode 100644
index 0000000..d9b275b
--- /dev/null
+++ b/src/main/java/com/demo/program/mapdemo/HashMapDemo.java
@@ -0,0 +1,54 @@
+package com.map;
+
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.Set;
+
+public class HashMapDemo {
+
+	public static void main(String[] args) {
+		
+		
+		HashMap<Integer,String> map = new HashMap<Integer, String>();
+		
+		map.put(new Integer(10), "Sakshi");
+		map.put(new Integer(20), "Palak");
+		map.put(40, "prachi");
+		map.put(40,"Ritesh");
+		map.put(50, "prachi");
+		map.put(null, "Hi");
+		map.put(null, "Hello");
+		map.put(60, null);
+		map.put(70,null);
+		
+		
+		//String s = map.get(10);
+		Set<Integer> keys = map.keySet();
+		
+		for(Integer k : keys)
+		{
+			System.out.println("Key :"+k+" Value: "+map.get(k));
+		}
+		
+		
+		HashMap<Employee, String> empmap = new HashMap<Employee, String>();
+		
+		Employee emp1=new Employee(101,"sakshi",1290);
+		Employee emp2=new Employee(101,"sakshi",1290);
+		Employee emp3=new Employee(103,"palak",34324);
+		
+		empmap.put(emp1, "Hi");
+		empmap.put(emp2, "Hello");
+		empmap.put(emp3, "Hi");
+		
+		Set<Employee> empset=empmap.keySet();
+		Iterator<Employee> it = empset.iterator();
+		while(it.hasNext())
+		{
+			Employee emp = it.next();
+			System.out.println("Key :"+emp+" Value: "+empmap.get(emp));
+		}	
+		
+	}
+	
+}
diff --git a/src/main/java/com/demo/program/mapdemo/HashTableDemo.java b/src/main/java/com/demo/program/mapdemo/HashTableDemo.java
new file mode 100644
index 0000000..b8d620e
--- /dev/null
+++ b/src/main/java/com/demo/program/mapdemo/HashTableDemo.java
@@ -0,0 +1,27 @@
+package com.map;
+
+import java.util.Hashtable;
+import java.util.Set;
+
+import com.map.Employee;
+
+public class HashTableDemo {
+
+	public static void main(String[] args) {
+		
+		Hashtable<Integer,Employee> map = new Hashtable<Integer, Employee>();
+		
+		map.put(1,new Employee(101,"Sakshi",1000));
+		map.put(2,new Employee(101, "Sakshi", 1000));
+		map.put(new Integer(4), new Employee(101, "Ritesh", 90000));
+		map.put(new Integer(6), new Employee(103, "Palak", 60000));
+		//map.put(5,null);
+		
+		Set<Integer> set = map.keySet();
+		for(Integer i : set)
+		{
+			System.out.println("Key: "+i+" Value: "+map.get(i));
+		}
+		
+	}
+}
diff --git a/src/main/java/com/demo/program/mapdemo/Student.java b/src/main/java/com/demo/program/mapdemo/Student.java
new file mode 100644
index 0000000..6aedeb9
--- /dev/null
+++ b/src/main/java/com/demo/program/mapdemo/Student.java
@@ -0,0 +1,34 @@
+package com.map;
+
+public class Student implements Comparable<Student>{
+	
+	private int rollNo;
+	private String name;
+	private float percentage;
+	public Student(int rollNo, String name, float percentage) {
+		super();
+		this.rollNo = rollNo;
+		this.name = name;
+		this.percentage = percentage;
+	}
+	@Override
+	public String toString() {
+		return "Student [rollNo=" + rollNo + ", name=" + name + ", percentage="
+				+ percentage + "]";
+	}
+	
+	public int compareTo(Student s)
+	{
+		return this.rollNo-s.rollNo;
+	}
+	public int getRollNo() {
+		return rollNo;
+	}
+	public String getName() {
+		return name;
+	}
+	public float getPercentage() {
+		return percentage;
+	}
+	
+}
diff --git a/src/main/java/com/demo/program/mapdemo/StudentComparator.java b/src/main/java/com/demo/program/mapdemo/StudentComparator.java
new file mode 100644
index 0000000..aeecc6f
--- /dev/null
+++ b/src/main/java/com/demo/program/mapdemo/StudentComparator.java
@@ -0,0 +1,15 @@
+package com.map;
+
+import java.util.Comparator;
+
+public class StudentComparator implements Comparator<Student>{
+
+	@Override
+	public int compare(Student s1, Student s2) {
+		
+		return s1.getName().compareTo(s2.getName());
+	}
+	
+	
+
+}
diff --git a/src/main/java/com/demo/program/mapdemo/TreeMapDemo.java b/src/main/java/com/demo/program/mapdemo/TreeMapDemo.java
new file mode 100644
index 0000000..2012c22
--- /dev/null
+++ b/src/main/java/com/demo/program/mapdemo/TreeMapDemo.java
@@ -0,0 +1,56 @@
+package com.map;
+
+import java.util.Set;
+import java.util.TreeMap;
+
+public class TreeMapDemo {
+
+	public static void main(String[] args) {
+		TreeMap< Integer, String> map = new TreeMap<Integer, String>();
+		
+		map.put(2,"Hi");
+		map.put(1, "Hello");
+		map.put(3, "Welcome");
+		
+		Set<Integer> keys = map.keySet();
+		for(Integer i : keys)
+		{
+			System.out.println("Key :"+i+" Value: "+map.get(i));
+		}
+		
+	    TreeMap<String,Employee> map1 = new TreeMap<String, Employee>();
+	    map1.put("Hi", new Employee(101,"Sakshi",1000));
+	    map1.put("Bitch", new Employee(102,"Palak",2000));
+	    
+	    Set<String> keys2 = map1.keySet();
+		for(String s : keys2)
+		{
+			System.out.println("Key :"+s+" Value: "+map1.get(s));
+		}
+	    
+		
+		TreeMap<Student,String> map2 = new TreeMap<Student, String>();
+		
+		map2.put(new Student(3,"Sakshi",87.3f), "hi");
+		map2.put(new Student(2,"Palak",85.3f), "hello");
+		map2.put(new Student(4,"Prachi",75.9f), "today");
+		
+		Set<Student> set = map2.keySet();
+		for(Student s : set)
+		{
+			System.out.println("Key: "+s+" Value: "+map2.get(s));
+		}
+		System.out.println("---------------------------------------------------");
+  
+		TreeMap<Student,String> map3 = new TreeMap<Student, String>(new StudentComparator()); 	
+		map3.put(new Student(3,"Sakshi",87.3f), "hi");
+        map3.put(new Student(2,"Palak",85.3f), "hello");
+		map3.put(new Student(4,"Prachi",75.9f), "today");
+		
+		Set<Student> set1 = map3.keySet();
+		for(Student s : set1)
+		{
+			System.out.println("Key: "+s+" Value: "+map3.get(s));
+		}
+	}
+}