Added Files

Author: imharshtiwari

Pillars-of-OOPS-In-Java/tempCodeRunnerFile.java

@@ -0,0 +1,3 @@
+public void speak() {
+        System.out.println("Human speaking");
+    }

Pillars-of-OOPS-In-Java/testHuman.java

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+
+class Monkey {
+    public void jump() {
+        System.out.println("Monkey juming");
+    }
+    
+    public void bite() {
+        System.out.println("Monkey biting");
+    }
+}
+interface BasicAnimal {
+    void Sleep();
+    void Eat();
+}
+
+class Human extends Monkey implements BasicAnimal {
+    
+    public void speak() {
+        System.out.println("Human speaking");
+    }
+    
+    @Override
+    public void Sleep() {
+        System.out.println("Human sleeping");
+    }
+    
+    @Override
+    public void Eat() {
+        System.out.println("Human eating");
+    }
+}
+
+public class testHuman {
+    public static void main(String[] args) {
+        Human human = new Human();
+        human.speak();
+        human.jump();
+        human.bite();
+        human.Sleep();
+        human.Eat();  // Polymorphism in action. Monkey's methods are overridden in Human class.
+        Monkey m = new Human();
+    
+        m.bite();  // Monkey calls this method when the user requests a bite 
+    }
+}

Pillars-of-OOPS-In-Java/testPen.java

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+   abstract class Pen {
+     abstract void write();
+     abstract void refill();
+
+   }
+   class FountainPen extends Pen {
+      void write() {
+        System.out.println("Writing on fountain pen");
+     }
+      void refill() {
+        System.out.println("Refilling fountain pen");
+     }
+      void changeNib() {
+        System.out.println("Changing Nib");
+     }
+
+    }
+
+public class testPen {
+    public static void main(String[] args) {
+        FountainPen pen = new FountainPen() ; 
+        pen.changeNib();
+        pen.write();
+    }
+}