From 6b6f88c64d9a4b2d26de5725dee24f3c459fb93c Mon Sep 17 00:00:00 2001
From: bk2dcradle <ankitsultana@gmail.com>
Date: Sun, 4 Oct 2015 01:47:09 +0530
Subject: Added abstract classes

---
 java.html.markdown | 68 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 68 insertions(+)

diff --git a/java.html.markdown b/java.html.markdown
index 928eb39f..2f41be81 100644
--- a/java.html.markdown
+++ b/java.html.markdown
@@ -451,6 +451,74 @@ public class ExampleClass extends ExampleClassParent implements InterfaceOne,
 	public void InterfaceTwoMethod() {
 	}
 }
+
+
+// Abstract Classes 
+// Abstract Class declaration syntax
+// <access-level> abstract <abstract-class-name> extends <super-abstract-classes> {
+//     // Constants and variables
+//     // Method declarations
+// }
+
+// Methods can't have bodies in an interface, unless the method is
+// static. Also variables are NOT final by default, unlike an interface.
+// Also abstract classes CAN have the "main" method.
+// Abstract classes solve these problems.
+
+public abstract class Animal 
+{
+	public abstract void makeSound();
+
+	// Method can have a body
+	public void eat()
+	{
+		System.out.println("I am an animal and I am Eating.");  
+		// Note: We can access private variable here.
+		age = 30;
+	}
+
+	// No need to initialise, however in an interface 
+	// a variable is implicitly final and hence has
+	// to be initialised.
+	private int age;
+
+	public void printAge()
+	{
+		System.out.println(age);  
+	}
+
+	// Abstract classes can have main function.
+	public static void main(String[] args)
+	{
+		System.out.println("I am abstract");
+	}
+}
+
+class Dog extends Animal
+{
+	// Note still have to override the abstract methods in the
+	// abstract class.
+	@Override
+	public void makeSound()
+	{
+		System.out.println("Bark");
+		// age = 30;	==> ERROR!	age is private to Animal
+	}
+
+	// NOTE: You will get an error if you used the 
+	// @Override annotation here, since java doesn't allow
+	// overriding of static methods.
+	// What is happening here is called METHOD HIDING.
+	// Check out this awesome SO post: (http://stackoverflow.com/questions/16313649/)
+	public static void main(String[] args)
+	{
+		Dog pluto = new Dog();
+		pluto.makeSound();
+		pluto.eat();
+		pluto.printAge();
+	}
+}
+
 ```
 
 ## Further Reading
-- 
cgit v1.2.3


From d8efd3ba3416669177683887b2822eb5d56c157b Mon Sep 17 00:00:00 2001
From: bk2dcradle <ankitsultana@gmail.com>
Date: Mon, 5 Oct 2015 01:38:02 +0530
Subject: Modified as said to by a Collaborator

---
 java.html.markdown | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/java.html.markdown b/java.html.markdown
index 2f41be81..89a710ee 100644
--- a/java.html.markdown
+++ b/java.html.markdown
@@ -477,9 +477,9 @@ public abstract class Animal
 		age = 30;
 	}
 
-	// No need to initialise, however in an interface 
+	// No need to initialize, however in an interface 
 	// a variable is implicitly final and hence has
-	// to be initialised.
+	// to be initialized.
 	private int age;
 
 	public void printAge()
@@ -509,7 +509,7 @@ class Dog extends Animal
 	// @Override annotation here, since java doesn't allow
 	// overriding of static methods.
 	// What is happening here is called METHOD HIDING.
-	// Check out this awesome SO post: (http://stackoverflow.com/questions/16313649/)
+	// Check out this awesome SO post: http://stackoverflow.com/questions/16313649/
 	public static void main(String[] args)
 	{
 		Dog pluto = new Dog();
-- 
cgit v1.2.3