OOP: Polymorphism

slgobinath · slgobinath · commit d96bc07bee23 · 2015-02-20T17:18:19.000+05:30
diff --git a/objectorientedprogramming/polymorphism/BankAccount.java b/objectorientedprogramming/polymorphism/BankAccount.java
@@ -0,0 +1,31 @@
+/**
+ * Sample class BankAccount which is used as the super class of CurrentAcoount and SavingsAccount.
+ *
+ * @version 1.0
+ * @author L.Gobinath
+ */
+public class BankAccount {
+    private String name;
+    private double balance;
+
+    public String getName() {
+        return this.name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public void deposite(double amount) {
+    	this.balance += amount;
+    }
+    
+    public boolean withdraw(double amount) {
+        if (balance > amount) {
+            balance -= amount;
+            return true;
+        } else {
+            return false;
+        }
+    }
+}
diff --git a/objectorientedprogramming/polymorphism/BankDemo.java b/objectorientedprogramming/polymorphism/BankDemo.java
@@ -0,0 +1,25 @@
+/**
+ * Testing class for BankAccounts.
+ *
+ * @version 1.0
+ * @author L.Gobinath
+ */
+public class BankDemo {
+    public static void main(String[] args) {
+        CurrentAccount c = new CurrentAccount();
+        SavingsAccount s = new SavingsAccount();
+        c.deposite(500.00);
+        s.deposite(500.00);
+        doWithdrawal(c);    // Withdraw succeed.
+        doWithdrawal(s);    // Withdraw failed.
+    }
+
+    public static void doWithdrawal(BankAccount acc) {
+        boolean result = acc.withdraw(1000.00);
+        if (result) {
+            System.out.println("Withdraw succeed.");
+        } else {
+            System.out.println("Withdraw failed.");
+        }
+    }
+}
diff --git a/objectorientedprogramming/polymorphism/CalculatorDemo/v1/CalculatorDemo.java b/objectorientedprogramming/polymorphism/CalculatorDemo/v1/CalculatorDemo.java
@@ -0,0 +1,25 @@
+/**
+ * Sample Calculator class to demonstrate Method Overloading.
+ *
+ * @version 1.0
+ * @author L.Gobinath
+ */
+public class CalculatorDemo {
+    public static void main(String[] args) {
+        Calculator calc = new Calculator();
+        calc.addLong(10L, 30L);
+        calc.addFloat(10.5f, 0.5f);
+    }
+}
+
+class Calculator {
+    public void addLong(long x, long y) {
+        long result = x + y;
+        System.out.println("Long addition: " + result);
+    }
+
+    public void addFloat(float x, float y) {
+        float result = x + y;
+        System.out.println("Float addition: " + result);
+    }
+}
diff --git a/objectorientedprogramming/polymorphism/CalculatorDemo/v2/CalculatorDemo.java b/objectorientedprogramming/polymorphism/CalculatorDemo/v2/CalculatorDemo.java
@@ -0,0 +1,28 @@
+/**
+ * Sample Calculator class to demonstrate Method Overloading.
+ *
+ * @version 2.0
+ * @author L.Gobinath
+ */
+public class CalculatorDemo {
+    public static void main(String[] args) {
+        Calculator calc = new Calculator();
+        calc.add(10L, 30L);
+        calc.add(10.5f, 0.5f);
+    }
+}
+
+/**
+ * Calculator class has two methods add(long, long) and add(float, float).
+ */
+class Calculator {
+    public void add(long x, long y) {
+        long result = x + y;
+        System.out.println("Long addition: " + result);
+    }
+
+    public void add(float x, float y) {
+        float result = x + y;
+        System.out.println("Float addition: " + result);
+    }
+}
diff --git a/objectorientedprogramming/polymorphism/CalculatorDemo/v3/CalculatorDemo.java b/objectorientedprogramming/polymorphism/CalculatorDemo/v3/CalculatorDemo.java
@@ -0,0 +1,30 @@
+/**
+ * Sample Calculator class to demonstrate Method Overloading.
+ *
+ * @version 3.0
+ * @author L.Gobinath
+ */
+public class CalculatorDemo {
+    public static void main(String[] args) {
+        Calculator calc = new Calculator();
+        // Passing two integer values
+        calc.add(10, 30);   // add(long, long)
+        // Passing two long values
+        calc.add(10L, 30L); // add(long, long)
+    }
+}
+
+/**
+ * Calculator class has two methods add(long, long) and add(float, float).
+ */
+class Calculator {
+    public void add(long x, long y) {
+        long result = x + y;
+        System.out.println("Long addition: " + result);
+    }
+
+    public void add(float x, float y) {
+        float result = x + y;
+        System.out.println("Float addition: " + result);
+    }
+}
diff --git a/objectorientedprogramming/polymorphism/CalculatorDemo/v4/CalculatorDemo.java b/objectorientedprogramming/polymorphism/CalculatorDemo/v4/CalculatorDemo.java
@@ -0,0 +1,30 @@
+/**
+ * Sample Calculator class to demonstrate Method Overloading.
+ *
+ * @version 4.0
+ * @author L.Gobinath
+ */
+public class CalculatorDemo {
+    public static void main(String[] args) {
+        Calculator calc = new Calculator();
+        // Passing two integer values
+        calc.add(10, 30);   // add(int, int)
+        // Passing two long values
+        calc.add(10L, 30L); // add(long, long)
+    }
+}
+
+/**
+ * Calculator class has two methods add(long, long) and add(int, int).
+ */
+class Calculator {
+    public void add(long x, long y) {
+        long result = x + y;
+        System.out.println("Long addition: " + result);
+    }
+
+    public void add(int x, int y) {
+        int result = x + y;
+        System.out.println("Integer addition: " + result);
+    }
+}
diff --git a/objectorientedprogramming/polymorphism/CovariantReturn.java b/objectorientedprogramming/polymorphism/CovariantReturn.java
@@ -0,0 +1,41 @@
+/**
+ * Covariant return example.
+ * Overriding method returns a subtype of overridden method's return type.
+ *
+ * @version 1.0
+ * @author L.Gobinath
+ */
+public class CovariantReturn {
+    public static void main(String[] args) {
+        create(new CircleFactory());
+    }
+
+    public static void create(ShapeFactory factory) {
+        Shape shape = factory.getShape();
+        // Circle circle = factory.getShape();  // Compile time error
+        shape.draw();   // Circle
+    }
+}
+
+class Shape {
+    public void draw() {
+        System.out.println("Shape");
+    }
+}
+class Circle extends Shape {
+    public void draw() {
+        System.out.println("Circle");
+    }
+}
+
+class ShapeFactory {
+    public Shape getShape() {
+        return new Shape();
+    }
+}
+
+class CircleFactory extends ShapeFactory {
+    public Circle getShape() {
+        return new Circle();
+    }
+}
diff --git a/objectorientedprogramming/polymorphism/CurrentAccount.java b/objectorientedprogramming/polymorphism/CurrentAccount.java
@@ -0,0 +1,9 @@
+/**
+ * CurrentAccount allows to have negative balance.
+ *
+ * @version 1.0
+ * @author L.Gobinath
+ */
+public class CurrentAccount extends BankAccount {
+
+}
diff --git a/objectorientedprogramming/polymorphism/SavingsAccount.java b/objectorientedprogramming/polymorphism/SavingsAccount.java
@@ -0,0 +1,9 @@
+/**
+ * SavingsAccount does not have any significant differences.
+ *
+ * @version 1.0
+ * @author L.Gobinath
+ */
+public class SavingsAccount extends BankAccount {
+
+}
