diff --git a/AbstractionDemo1.java b/AbstractionDemo1.java
new file mode 100644
index 0000000..41a2516
--- /dev/null
+++ b/AbstractionDemo1.java
@@ -0,0 +1,25 @@
+abstract class Shape{
+	abstract void draw();
+	public void paint(){
+		System.out.println("rainbow...");
+	}
+}
+class Rectangle extends Shape{
+	public void draw(){
+		System.out.println("Draw a rectangle...");
+	}
+}
+class Circle extends Shape{
+	public void draw(){
+		System.out.println("Draw a circle...");
+	}
+}
+class AbstractionDemo1{			
+	public static void main(String[] args){
+		Shape shape = new Rectangle();
+		shape.draw();
+		shape.paint();
+		shape = new Circle();
+		shape.draw();
+	}
+}
\ No newline at end of file
diff --git a/AbstractionDemo2.java b/AbstractionDemo2.java
new file mode 100644
index 0000000..dd79050
--- /dev/null
+++ b/AbstractionDemo2.java
@@ -0,0 +1,25 @@
+interface Shape{
+	void draw();
+	public static void paint(){
+		System.out.println("rainbow...");
+	}
+}
+class Rectangle implements Shape{
+	public void draw(){
+		System.out.println("Draw a rectangle...");
+	}
+}
+class Circle implements Shape{
+	public void draw(){
+		System.out.println("Draw a circle...");
+	}
+}
+class AbstractionDemo2{			
+	public static void main(String[] args){
+		Shape shape = new Rectangle();
+		shape.draw();
+		Shape.paint();
+		shape = new Circle();
+		shape.draw();
+	}
+}
\ No newline at end of file
diff --git a/Abstraction_demo/AbstractDemo.java b/Abstraction_demo/AbstractDemo.java
new file mode 100644
index 0000000..c561f05
--- /dev/null
+++ b/Abstraction_demo/AbstractDemo.java
@@ -0,0 +1,30 @@
+package pck2;
+import pck1.Car;
+import pck1.Vehicle;
+import pck1.MotorCycle;
+import java.util.Scanner;
+ 
+class AbstractDemo{
+	public static void main(String[] args){
+		String brand;
+		int d;
+		Scanner sc = new Scanner(System.in);
+		System.out.println("Enter gaadi name : ");
+		brand = sc.next();
+		System.out.println("Kitna chalaoge : ");
+		d = sc.nextInt();
+		Car car = new Car(brand);
+		Vehicle v = car;
+		MotorCycle bike = new MotorCycle(brand);
+		Buyer mansi = new Buyer(bike);
+		
+		Buyer ekansh = new Buyer(new Vehicle(){
+			public void move(int distance){
+				System.out.println("dhrooommmmmmmmm : "+distance);
+			}
+		});
+		ekansh.gaadiChal(1000);
+		mansi.gaadiChal(d);
+	}
+}
+
diff --git a/Abstraction_demo/Buyer.java b/Abstraction_demo/Buyer.java
new file mode 100644
index 0000000..d355764
--- /dev/null
+++ b/Abstraction_demo/Buyer.java
@@ -0,0 +1,13 @@
+package pck2;
+import pck1.Vehicle;
+
+class Buyer{
+	Vehicle gaadi;
+	Buyer(Vehicle v){
+		gaadi = v;
+	}
+	public void gaadiChal(int d){
+		gaadi.move(d);
+	}
+}
+
diff --git a/Abstraction_demo/Car.java b/Abstraction_demo/Car.java
new file mode 100644
index 0000000..3b072cc
--- /dev/null
+++ b/Abstraction_demo/Car.java
@@ -0,0 +1,13 @@
+package pck1;
+
+public class Car implements Vehicle{
+	String brand;
+	public Car(String b){
+		brand = b;
+	}
+	public void move(int distance){
+		System.out.println("brand : "+brand);
+		System.out.println("distance : "+distance);
+	}
+}
+
diff --git a/Abstraction_demo/MotorCycle.java b/Abstraction_demo/MotorCycle.java
new file mode 100644
index 0000000..715d545
--- /dev/null
+++ b/Abstraction_demo/MotorCycle.java
@@ -0,0 +1,13 @@
+package pck1;
+
+public class MotorCycle implements Vehicle{
+	String brand;
+	public MotorCycle(String b){
+		brand = b;
+	}
+	public void move(int distance){
+		System.out.println("Motor brand : "+brand);
+		System.out.println("distance : "+distance);
+	}
+}
+
diff --git a/Abstraction_demo/RealWorldInterfaceEx.java b/Abstraction_demo/RealWorldInterfaceEx.java
new file mode 100644
index 0000000..7a67565
--- /dev/null
+++ b/Abstraction_demo/RealWorldInterfaceEx.java
@@ -0,0 +1,59 @@
+import java.util.Scanner;
+
+interface Transportation{
+	int getRatePerKm();
+	int getFixedCharge();
+	default float getFare(float distance){
+		float fare = getFixedCharge() + (distance - 1) * getRatePerKm();
+		return fare;
+	}
+}
+class Metro implements Transportation{
+	public int getRatePerKm(){
+		return 5;
+	}
+	public int getFixedCharge(){
+		return 10;
+	}
+}
+class Ola implements Transportation{
+	public int getRatePerKm(){
+		return 6;
+	}
+	public int getFixedCharge(){
+		return 25;
+	}
+}
+
+class ByWalk implements Transportation{
+	public int getRatePerKm(){
+		return 0;
+	}
+	public int getFixedCharge(){
+		return 0;
+	}
+}
+
+public class RealWorldInterfaceEx{
+	public static void main(String[] args){
+		Scanner sc = new Scanner(System.in);
+		System.out.println("Hello  please select mode of transportation : ");
+		System.out.println("Options are : ");
+		System.out.println("1. Metro");
+		System.out.println("2. Ola");
+		int choice = sc.nextInt();
+		Transportation transportation = null;
+		switch(choice){
+			case 1 : transportation = new Metro();break;
+			case 2 : transportation = new Ola();break;
+			default : transportation = new ByWalk();break;
+		}
+		System.out.println("Enter distance : ");
+		int distance = sc.nextInt();
+		float fare = transportation.getFare(distance);
+		System.out.println("fare : "+fare);
+	}
+}
+
+
+
diff --git a/Abstraction_demo/Vehicle.java b/Abstraction_demo/Vehicle.java
new file mode 100644
index 0000000..45d5a6a
--- /dev/null
+++ b/Abstraction_demo/Vehicle.java
@@ -0,0 +1,6 @@
+package pck1;
+
+public interface Vehicle{
+	public void move(int distance);
+}
+
diff --git a/AggregationDemo2.java b/AggregationDemo2.java
new file mode 100644
index 0000000..0410a44
--- /dev/null
+++ b/AggregationDemo2.java
@@ -0,0 +1,37 @@
+class Address{
+	int hNo;
+	String street;
+	int pincode;
+	String city;
+	public Address(int hNo,String street,int pincode,String city){
+		this.hNo = hNo;
+		this.street = street;
+		this.pincode = pincode;
+		this.city = city;
+	}
+	@Override
+	public String toString(){
+		return "Address{\n house no : "+hNo+",\n street : "+street+",\n pincode : "+pincode+",\n city : "+city+"}";
+	}
+}
+class Student{
+	int rn;
+	String name;
+	Address addr;
+	public Student(int rn,String name,Address addr){
+		this.rn = rn;
+		this.name = name;
+		this.addr = addr;
+	}
+	@Override
+	public String toString(){
+		return "Student{\n roll no :"+rn+",\n name : "+name+",\n address : "+addr+"}";
+	}
+}
+class AggregationDemo2{
+	public static void main(String[] args){
+		Address addr = new Address(108,"A- Block",110033,"Delhi");
+		Student s = new Student(1,"Tanishq",addr);
+		System.out.println(s);
+	}
+}
\ No newline at end of file
diff --git a/Comparator and Comparable demo/ComparatorAndComparabaleDemo.java b/Comparator and Comparable demo/ComparatorAndComparabaleDemo.java
new file mode 100644
index 0000000..6a55a84
--- /dev/null
+++ b/Comparator and Comparable demo/ComparatorAndComparabaleDemo.java	
@@ -0,0 +1,46 @@
+/*
+ * To change this license header, choose License Headers in Project Properties.
+ * To change this template file, choose Tools | Templates
+ * and open the template in the editor.
+ */
+package comparatorandcomparabaledemo;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+/**
+ *
+ * @author cm
+ */
+public class ComparatorAndComparabaleDemo {
+
+    /**
+     * @param args the command line arguments
+     */
+    public static void main(String[] args) {
+        // TODO code application logic here
+        List<Integer> rankingList = new ArrayList<>();
+        rankingList.add(23);
+        rankingList.add(2);
+        rankingList.add(43);
+        rankingList.add(86);
+        rankingList.add(8);
+        rankingList.add(89);
+        rankingList.add(65);
+        rankingList.add(265);
+        Collections.sort(rankingList);
+        //System.out.println(rankingList);
+        List<Student> list = new ArrayList<>();
+        list.add(new Student(1,"Rinku",100));
+        list.add(new Student(2,"Piyush",10));
+        list.add(new Student(4,"Ramu",60));
+        list.add(new Student(5,"Ashna",80));
+        list.add(new Student(3,"Sanyam",22));
+        list.add(new Student(6,"Tushar",1));
+        MarksComparator marksComparator = new MarksComparator();
+        Collections.sort(list,marksComparator);
+        System.out.println(list);
+    }
+    
+}
diff --git a/Comparator and Comparable demo/MarksComparator.java b/Comparator and Comparable demo/MarksComparator.java
new file mode 100644
index 0000000..809b146
--- /dev/null
+++ b/Comparator and Comparable demo/MarksComparator.java	
@@ -0,0 +1,27 @@
+/*
+ * To change this license header, choose License Headers in Project Properties.
+ * To change this template file, choose Tools | Templates
+ * and open the template in the editor.
+ */
+package comparatorandcomparabaledemo;
+
+import java.util.Comparator;
+
+/**
+ *
+ * @author cm
+ */
+public class MarksComparator implements Comparator<Student>{
+
+    @Override
+    public int compare(Student o1, Student o2) {
+        if(o1.getMarks()>o2.getMarks()){
+            return -1;
+        }else if(o1.getMarks()==o2.getMarks()){
+            return 0;
+        }else{
+            return 1;
+        }
+    }
+    
+}
diff --git a/Comparator and Comparable demo/Student.java b/Comparator and Comparable demo/Student.java
new file mode 100644
index 0000000..fcaa013
--- /dev/null
+++ b/Comparator and Comparable demo/Student.java	
@@ -0,0 +1,70 @@
+/*
+ * To change this license header, choose License Headers in Project Properties.
+ * To change this template file, choose Tools | Templates
+ * and open the template in the editor.
+ */
+package comparatorandcomparabaledemo;
+
+/**
+ *
+ * @author cm
+ */
+public class Student implements Comparable<Student>{
+    private int rn;
+    private String name;
+    private float marks;
+
+    public Student() {
+    }
+
+    public Student(int rn, String name, float marks) {
+        this.rn = rn;
+        this.name = name;
+        this.marks = marks;
+    }
+
+    
+    
+    public int getRn() {
+        return rn;
+    }
+
+    public void setRn(int rn) {
+        this.rn = rn;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public float getMarks() {
+        return marks;
+    }
+
+    public void setMarks(float marks) {
+        this.marks = marks;
+    }
+
+    @Override
+    public String toString() {
+        return "Student{" + "rn=" + rn + ", name=" + name + ", marks=" + marks + '}';
+    }
+
+    @Override
+    public int compareTo(Student o) {
+        int anotherRn = o.getRn();
+        if(rn>anotherRn){
+            return 1;
+        }else if(anotherRn == rn){
+            return 0;
+        }else{
+            return -1;
+        }
+    }
+    
+    
+}
diff --git a/ConsoleDemo.java b/ConsoleDemo.java
new file mode 100644
index 0000000..fbee957
--- /dev/null
+++ b/ConsoleDemo.java
@@ -0,0 +1,36 @@
+package com.cmpundhir;
+
+import java.io.Console;
+
+class ConsoleDemo{
+	private static String savedUsername = "cmpundhir";
+	private static char[] savedPassword = {'s','t','r','o','n','g'};
+	
+	private static boolean isVerified(String un,char[] ps){
+		if(un.equals(savedUsername)){
+			for(int i=0;i<savedPassword.length;i++){
+				if(savedPassword[i]!=ps[i]){
+					System.out.println("Incorrect Password");
+					return false;
+				}
+			}
+		}else{
+			System.out.println("Incorrect username");
+			return false;
+		}
+		return true;
+	}
+	public static void main(String[] args){
+		String username;
+		char[] password;
+		System.out.println("Enter username : ");
+		Console con = System.console();
+		username = con.readLine();
+		System.out.println("Enter password : ");
+		password = con.readPassword();
+		if(isVerified(username,password)){
+			System.out.println("Welcome "+username);
+		}
+	
+	}
+}
\ No newline at end of file
diff --git a/ExceptionHandling.java b/ExceptionHandling.java
new file mode 100644
index 0000000..46a015a
--- /dev/null
+++ b/ExceptionHandling.java
@@ -0,0 +1,22 @@
+import java.util.*;
+class ExceptionHandling{
+	public static void main(String[] args){
+		Scanner sc = new Scanner(System.in);
+		int a=0,b,c;
+		try{
+			System.out.println("Enter a = ");
+			a = sc.nextInt();
+			System.out.println("Enter b = ");
+			b = sc.nextInt();
+			c = a / b;
+			System.out.println(c);
+		}catch(ArithmeticException e){
+			System.out.println(e);
+		}
+		finally{
+			System.out.println("I am finally and i always run...");
+		}
+		System.out.println("program is still working...");
+		
+	}
+}
\ No newline at end of file
diff --git a/ExceptionHandling2.java b/ExceptionHandling2.java
new file mode 100644
index 0000000..76712aa
--- /dev/null
+++ b/ExceptionHandling2.java
@@ -0,0 +1,28 @@
+import java.util.*;
+class AgeException extends Exception{
+	public AgeException(String msg){
+		super(msg);
+	}
+}
+class ExceptionHandling2{
+	private static void verifyAge(int age) throws AgeException{
+		if(age<18){
+			throw new AgeException("You can not vote");
+		}else{
+			System.out.println("you can vote");
+		}
+	}
+	public static void main(String[] args){
+		Scanner sc = new Scanner(System.in);
+		System.out.println("Enter your age : ");
+		int age = sc.nextInt();
+		try{
+			verifyAge(age);
+		}catch(AgeException e){
+			System.out.println(e);
+		}
+		finally{
+			System.out.println("I am finally and i always run...");
+		}
+	}
+}
\ No newline at end of file
diff --git a/FIleIODemo7.java b/FIleIODemo7.java
new file mode 100644
index 0000000..58c17c9
--- /dev/null
+++ b/FIleIODemo7.java
@@ -0,0 +1,19 @@
+import java.io.FileInputStream;
+import java.io.SequenceInputStream;
+import java.util.Scanner;
+
+class FileIODemo7{
+	public static void main(String[] args){
+		try{
+			FileInputStream fin1 = new FileInputStream("E:\\JAVA\\Java Classes Programs\\HelloIO5.txt");
+			FileInputStream fin2 = new FileInputStream("E:\\JAVA\\Java Classes Programs\\HelloIO.txt");
+			SequenceInputStream bin = new SequenceInputStream(fin1,fin2);
+			int a = 0;
+			while((a = bin.read())!= -1){
+				System.out.print((char)a);
+			}
+		}catch(Exception e){
+			System.err.println(e.getMessage());
+		}
+	}
+}
\ No newline at end of file
diff --git a/FileIODemo.java b/FileIODemo.java
new file mode 100644
index 0000000..c3936a5
--- /dev/null
+++ b/FileIODemo.java
@@ -0,0 +1,15 @@
+import java.io.FileOutputStream;
+
+
+class FileIODemo{
+	public static void main(String[] args){
+		try{
+		FileOutputStream fout = new FileOutputStream("E:\\JAVA\\Java Classes Programs\\HelloIO1.txt");
+		fout.write(65);
+		fout.close();
+		System.out.println("Success");
+		}catch(Exception e){
+			System.err.println(e.getMessage());
+		}
+	}
+}
\ No newline at end of file
diff --git a/FileIODemo2.java b/FileIODemo2.java
new file mode 100644
index 0000000..8715af3
--- /dev/null
+++ b/FileIODemo2.java
@@ -0,0 +1,19 @@
+import java.io.FileOutputStream;
+import java.util.Scanner;
+
+class FileIODemo2{
+	public static void main(String[] args){
+		try{
+			Scanner sc = new Scanner(System.in);
+			FileOutputStream fout = new FileOutputStream("E:\\JAVA\\Java Classes Programs\\HelloIO.txt");
+			System.out.println("Enter a message : ");
+			String msg = sc.nextLine();
+			byte[] arr = msg.getBytes();
+			fout.write(arr);
+			fout.close();
+			System.out.println("Success");
+		}catch(Exception e){
+			System.err.println(e.getMessage());
+		}
+	}
+}
\ No newline at end of file
diff --git a/FileIODemo3.java b/FileIODemo3.java
new file mode 100644
index 0000000..71864b2
--- /dev/null
+++ b/FileIODemo3.java
@@ -0,0 +1,15 @@
+import java.io.FileInputStream;
+import java.util.Scanner;
+
+class FileIODemo3{
+	public static void main(String[] args){
+		try{
+			FileInputStream fin = new FileInputStream("E:\\JAVA\\Java Classes Programs\\HelloIO1.txt");
+			int a = fin.read();
+			System.out.println((char)a);
+			System.out.println("Success");
+		}catch(Exception e){
+			System.err.println(e.getMessage());
+		}
+	}
+}
\ No newline at end of file
diff --git a/FileIODemo4.java b/FileIODemo4.java
new file mode 100644
index 0000000..b454ff2
--- /dev/null
+++ b/FileIODemo4.java
@@ -0,0 +1,17 @@
+import java.io.FileInputStream;
+import java.util.Scanner;
+
+class FileIODemo4{
+	public static void main(String[] args){
+		try{
+			FileInputStream fin = new FileInputStream("E:\\JAVA\\Java Classes Programs\\HelloIO.txt");
+			int a = 0;
+			while((a = fin.read())!= -1){
+				System.err.print((char)a);
+			}
+			System.out.println("Success");
+		}catch(Exception e){
+			System.err.println(e);
+		}
+	}
+}
\ No newline at end of file
diff --git a/FileIODemo5.java b/FileIODemo5.java
new file mode 100644
index 0000000..dae8f13
--- /dev/null
+++ b/FileIODemo5.java
@@ -0,0 +1,22 @@
+import java.io.FileOutputStream;
+import java.io.BufferedOutputStream;
+import java.util.Scanner;
+
+class FileIODemo5{
+	public static void main(String[] args){
+		try{
+			Scanner sc = new Scanner(System.in);
+			FileOutputStream fin = new FileOutputStream("E:\\JAVA\\Java Classes Programs\\HelloIO5.txt");
+			BufferedOutputStream buff = new BufferedOutputStream(fin);
+			System.out.println("Enter a message : ");
+			String msg = sc.nextLine();
+			byte[] arr = msg.getBytes();
+			buff.write(arr);
+			buff.flush();
+			buff.close();
+			System.out.println("Success");
+		}catch(Exception e){
+			System.err.println(e);
+		}
+	}
+}
\ No newline at end of file
diff --git a/FileIODemo6.java b/FileIODemo6.java
new file mode 100644
index 0000000..9f68aef
--- /dev/null
+++ b/FileIODemo6.java
@@ -0,0 +1,19 @@
+import java.io.FileInputStream;
+import java.io.BufferedInputStream;
+import java.util.Scanner;
+
+class FileIODemo6{
+	public static void main(String[] args){
+		try{
+			FileInputStream fin = new FileInputStream("E:\\JAVA\\Java Classes Programs\\HelloIO5.txt");
+			BufferedInputStream bin = new BufferedInputStream(fin);
+			int a = 0;
+			while((a = bin.read())!= -1){
+				System.out.print((char)a);
+			}
+			System.out.println("Success");
+		}catch(Exception e){
+			System.err.println(e.getMessage());
+		}
+	}
+}
\ No newline at end of file
diff --git a/FileIODemo8.java b/FileIODemo8.java
new file mode 100644
index 0000000..8600987
--- /dev/null
+++ b/FileIODemo8.java
@@ -0,0 +1,25 @@
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.SequenceInputStream;
+import java.util.Scanner;
+
+class FileIODemo8{
+	public static void main(String[] args){
+		try{
+			FileInputStream fin1 = new FileInputStream("E:\\JAVA\\Java Classes Programs\\HelloIO5.txt");
+			FileInputStream fin2 = new FileInputStream("E:\\JAVA\\Java Classes Programs\\HelloIO.txt");
+			FileOutputStream fout = new FileOutputStream("E:\\JAVA\\Java Classes Programs\\SequenceOutput.txt");
+			SequenceInputStream bin = new SequenceInputStream(fin1,fin2);
+			int a = 0;
+			while((a = bin.read())!= -1){
+				fout.write(a);
+			}
+			fin1.close();
+			fin2.close();
+			fout.close();
+			bin.close();
+		}catch(Exception e){
+			System.err.println(e.getMessage());
+		}
+	}
+}
\ No newline at end of file
diff --git a/FileIODemo9.java b/FileIODemo9.java
new file mode 100644
index 0000000..5634358
--- /dev/null
+++ b/FileIODemo9.java
@@ -0,0 +1,35 @@
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.SequenceInputStream;
+import java.util.*;
+
+class FileIODemo9{
+	public static void main(String[] args){
+		try{
+			FileInputStream fin1 = new FileInputStream("E:\\JAVA\\Java Classes Programs\\HelloIO5.txt");
+			FileInputStream fin2 = new FileInputStream("E:\\JAVA\\Java Classes Programs\\HelloIO.txt");
+			FileInputStream fin3 = new FileInputStream("E:\\JAVA\\Java Classes Programs\\HelloIO5.txt");
+			FileInputStream fin4 = new FileInputStream("E:\\JAVA\\Java Classes Programs\\HelloIO.txt");
+			FileOutputStream fout = new FileOutputStream("E:\\JAVA\\Java Classes Programs\\SequenceOutput2.txt");
+			
+			Vector<FileInputStream> vector = new Vector<FileInputStream>();
+			vector.add(fin1);
+			vector.add(fin2);
+			vector.add(fin3);
+			vector.add(fin4);
+			
+			Enumeration<FileInputStream> enm = vector.elements();
+			SequenceInputStream bin = new SequenceInputStream(enm);
+			int a = 0;
+			while((a = bin.read())!= -1){
+				fout.write(a);
+			}
+			fin1.close();
+			fin2.close();
+			fout.close();
+			bin.close();
+		}catch(Exception e){
+			System.err.println(e.getMessage());
+		}
+	}
+}
\ No newline at end of file
diff --git a/Input.java b/Input.java
new file mode 100644
index 0000000..6e56c0b
--- /dev/null
+++ b/Input.java
@@ -0,0 +1,9 @@
+import java.util.Scanner;
+
+class Input{
+	public static void main(String[] args){
+		Scanner sc = new Scanner(System.in);
+		String name = sc.next();
+		int a = sc.nextInt();
+	}
+}
\ No newline at end of file
diff --git a/MultipleInheritance.java b/MultipleInheritance.java
new file mode 100644
index 0000000..a9464bd
--- /dev/null
+++ b/MultipleInheritance.java
@@ -0,0 +1,40 @@
+interface A{
+	public void method();
+}
+interface B{
+	public void method();
+}
+class C implements B,A{
+	public void method(){
+		System.out.println("I am A");
+	}
+}
+class MultipleInheritance{
+	public static void main(String[] args){
+		C c = new C();
+		c.method();
+		
+		A a = new A(){
+			@Override
+			public void method(){
+				System.out.println("Hello Method");
+			}
+		};
+		a.method();
+		
+		//annonymous object
+		
+		new C().method();
+		
+		new A(){
+			@Override
+			public void method(){
+				System.out.println("I am annonymously created and overriden");
+			}
+		}.method();
+	}
+}
+
+
+
+
diff --git a/Oops4.java b/Oops4.java
new file mode 100644
index 0000000..3302d7c
--- /dev/null
+++ b/Oops4.java
@@ -0,0 +1,46 @@
+abstract class BeingSundar{
+	abstract void goods();
+	abstract void bads();
+	public void complications(){
+		System.out.println("it's complicated...");
+	}
+}	
+class Mayank extends BeingSundar{
+	@Override
+	public void goods(){
+		System.out.println("1. Sundar ladkiyo ki kami nhi...");
+		System.out.println("2. Overconfidence ki me bahot sundar hu...");
+		System.out.println("3. Modeling kr skte hai...");
+	}
+	@Override
+	public void bads(){
+		System.out.println("1. Dosro ko judge ya comment krna ...");
+		System.out.println("2. Shoes ka color match krna chahiye");
+		System.out.println("3. ladkiyo ki kami nhi...");
+	}
+	public void intro(){
+		System.out.println("i am mayank...");
+	}
+}
+class Priya extends BeingSundar{
+	public void goods(){
+		System.out.println("1. kuchh bhi pahan lo achhe lagte ho...");
+	}
+	@Override
+	public void bads(){
+		System.out.println("1. ladko ki lammbi line...");
+	}
+}
+
+class Oops4{
+	public static void main(String[] args){
+		BeingSundar sundar = new Mayank();
+		sundar.goods();
+		sundar.bads();
+		sundar.complications();
+		
+		sundar = new Priya();
+		sundar.goods();
+		sundar.bads();
+	}
+}
\ No newline at end of file
diff --git a/Oops5.java b/Oops5.java
new file mode 100644
index 0000000..39ede09
--- /dev/null
+++ b/Oops5.java
@@ -0,0 +1,72 @@
+interface BeingSundar{
+	void goods();
+	void bads();
+	/*public void complications(){
+		System.out.println("it's complicated...");
+	}*///interface cannot have a body method
+	default void complications(){
+		System.out.println("it's complicated...");
+	}
+}	
+class Mayank implements BeingSundar{
+	@Override
+	public void goods(){
+		System.out.println("1. Sundar ladkiyo ki kami nhi...");
+		System.out.println("2. Overconfidence ki me bahot sundar hu...");
+		System.out.println("3. Modeling kr skte hai...");
+	}
+	@Override
+	public void bads(){
+		System.out.println("1. Dosro ko judge ya comment krna ...");
+		System.out.println("2. Shoes ka color match krna chahiye");
+		System.out.println("3. ladkiyo ki kami nhi...");
+	}
+	public void intro(){
+		System.out.println("i am mayank...");
+	}
+}
+class Priya implements BeingSundar{
+	public void goods(){
+		System.out.println("1. kuchh bhi pahan lo achhe lagte ho...");
+	}
+	@Override
+	public void bads(){
+		System.out.println("1. ladko ki lammbi line...");
+	}
+}
+
+class Oops5{
+	public static void main(String[] args){
+		BeingSundar sundar = new Mayank();
+		sundar.goods();
+		sundar.bads();
+		sundar.complications();
+		
+		sundar = new Priya();
+		sundar.goods();
+		sundar.bads();
+		
+		sundar = new BeingSundar(){
+			public void goods(){
+				System.out.println("1. Bachhe bhi sundar hoge");
+			}
+			@Override
+			public void bads(){
+				System.out.println("1. koi gaurantee nhi hai bachha gora hoga...");
+			}
+		};
+		sundar.goods();
+		sundar.bads();
+		
+		new BeingSundar(){
+			public void goods(){
+				System.out.println("1. Ease to interact and get attention easily");
+				System.out.println("2. Easy friendship");
+			}
+			@Override
+			public void bads(){
+				System.out.println("1. Jalne wale log...");
+			}
+		}.goods();
+	}
+}
\ No newline at end of file
diff --git a/PackageDemo.java b/PackageDemo.java
new file mode 100644
index 0000000..abedccc
--- /dev/null
+++ b/PackageDemo.java
@@ -0,0 +1,9 @@
+package com.cmpundhir;
+
+class PackageDemo{
+	public static void main(String[] args){
+		System.out.println("command to create a package and run program is given below");
+		System.out.println("1. javac -d . PackageDemo.java");
+		System.out.println("2. java com.cmpundhir.PackageDemo");
+	}
+}
\ No newline at end of file
diff --git a/PolymorphismDemo1.java b/PolymorphismDemo1.java
new file mode 100644
index 0000000..93feda4
--- /dev/null
+++ b/PolymorphismDemo1.java
@@ -0,0 +1,23 @@
+//Type of polymorphism
+//1. static - overloading
+//2. Duynamic - overriding
+class PolymorphismDemo1{
+	
+	public static int add(int a,int b){
+		return a+b;
+	}
+	//overloading by changing number of parameters
+	public static int add(int a,int b,int c){
+		return a+b+c;
+	}
+	//overloading by changing datatype
+	public static float add(float a, float b){
+		return a+b;
+	}
+	public static void main(String[] args){
+		System.out.println(add(1,2));
+		System.out.println(add(1,2,3));
+		System.out.println(add(1.0f,2.3f));
+		System.out.println(add(1,2.3f));//automatic type casting / type promotion
+	}
+}
\ No newline at end of file
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..4bfbe16
--- /dev/null
+++ b/README.md
@@ -0,0 +1,6 @@
+# JavaExamples
+Java examples for beginners
+
+Hello coders , if you are beginner in coding and want to try few programs in java then here are some basic programs on java concepts. So you can try it.
+
+Happy coding.
diff --git a/SynchronisationDemo.java b/SynchronisationDemo.java
new file mode 100644
index 0000000..a605aab
--- /dev/null
+++ b/SynchronisationDemo.java
@@ -0,0 +1,28 @@
+class Table{
+	public synchronized void printTable(int n){
+		for(int i=1;i<11;i++){
+			System.out.println(n*i);
+			try{Thread.sleep(200);}catch(Exception e){}
+		}
+	}
+}
+class MyThread extends Thread{
+	Table t;
+	int n;
+	MyThread(Table t,int n){
+		this.t = t;
+		this.n = n;
+	}
+	public void run(){
+		t.printTable(n);
+	}
+}
+class SynchronisationDemo{
+	public static void main(String[] args){
+		Table tb = new Table();
+		MyThread t = new MyThread(tb,5);
+		t.start();
+		MyThread t2 = new MyThread(tb,50);
+		t2.start();
+	}
+}
\ No newline at end of file
diff --git a/SynchronizationDemo2.java b/SynchronizationDemo2.java
new file mode 100644
index 0000000..9daf382
--- /dev/null
+++ b/SynchronizationDemo2.java
@@ -0,0 +1,31 @@
+class Table{
+	public static synchronized void printTable(int n){
+		for(int i=1;i<11;i++){
+			System.out.println(n*i);
+			try{Thread.sleep(200);}catch(Exception e){}
+		}
+	}
+}
+class MyThread extends Thread{
+	Table t;
+	int n;
+	MyThread(Table t,int n){
+		this.t = t;
+		this.n = n;
+	}
+	public void run(){
+		t.printTable(n);
+	}
+}
+class SynchronizationDemo2{
+	public static void main(String[] args){
+		Table tb = new Table();
+		MyThread t = new MyThread(tb,5);
+		t.start();
+		//created another table object so now both thread have different resources so we
+		//need static synchronization 
+		Table tb2 = new Table();
+		MyThread t2 = new MyThread(tb2,50);
+		t2.start();
+	}
+}
\ No newline at end of file
diff --git a/SynchronizationDemo3.java b/SynchronizationDemo3.java
new file mode 100644
index 0000000..122a1ad
--- /dev/null
+++ b/SynchronizationDemo3.java
@@ -0,0 +1,31 @@
+class Table{
+	public void printTable(int n){
+		synchronized(this){
+			for(int i=1;i<11;i++){
+				System.out.println(n*i);
+				try{Thread.sleep(200);}catch(Exception e){}
+			}
+		}
+	}
+}
+class MyThread extends Thread{
+	Table t;
+	int n;
+	MyThread(Table t,int n){
+		this.t = t;
+		this.n = n;
+	}
+	public void run(){
+		t.printTable(n);
+	}
+}
+class SynchronizationDemo3{
+	public static void main(String[] args){
+		Table tb = new Table();
+		MyThread t = new MyThread(tb,5);
+		t.start();
+	
+		MyThread t2 = new MyThread(tb,50);
+		t2.start();
+	}
+}
\ No newline at end of file
diff --git a/SynchronizationDemo4DeadLock.java b/SynchronizationDemo4DeadLock.java
new file mode 100644
index 0000000..463f914
--- /dev/null
+++ b/SynchronizationDemo4DeadLock.java
@@ -0,0 +1,37 @@
+class SynchronizationDemo4DeadLock{
+	
+	public static void main(String[] args){
+		final String res1 = "Icecream";
+		final String res2 = "Chocolate";
+		Thread t1 = new Thread(){
+			public void run(){
+				synchronized(res1){
+					System.out.println(res1+" is locked by "+getName());
+					try{Thread.sleep(200);}catch(Exception e){}
+					synchronized(res2){
+						System.out.println(res2+" is locked by "+getName());
+						try{Thread.sleep(200);}catch(Exception e){}
+						System.out.println(res2+" is released by "+getName());
+					}
+					System.out.println(res1+" is released by "+getName());
+				}
+			}
+		};
+		t1.start();
+		Thread t2 = new Thread(){
+			public void run(){
+				synchronized(res2){
+					System.out.println(res2+" is locked by "+getName());
+					try{Thread.sleep(200);}catch(Exception e){}
+					synchronized(res1){
+						System.out.println(res1+" is locked by "+getName());
+						try{Thread.sleep(200);}catch(Exception e){}
+						System.out.println(res1+" is released by "+getName());
+					}
+					System.out.println(res2+" is released by "+getName());
+				}
+			}
+		};
+		t2.start();
+	}
+}
\ No newline at end of file