Method Overloading and Overriding in Java - BAEL-1507 (#3621)

* Initial Commit

* Update Multiplier.java

* Refactored MethodOverridingUnitTest class

* Update Car.java

* Update Vehicle.java

* Update MethodOverridingUnitTest.java

* Update MethodOverridingUnitTest.java

* Fix package names

core-java/src/main/java/com/baeldung/methodoverloadingoverriding/application/Application.java

@@ -0,0 +1,26 @@
+package com.baeldung.methodoverloadingoverriding.application;
+
+import com.baeldung.methodoverloadingoverriding.model.Car;
+import com.baeldung.methodoverloadingoverriding.model.Vehicle;
+import com.baeldung.methodoverloadingoverriding.util.Multiplier;
+
+public class Application {
+    
+    public static void main(String[] args) {
+        Multiplier multiplier = new Multiplier();
+        System.out.println(multiplier.multiply(10, 10));
+        System.out.println(multiplier.multiply(10, 10, 10));
+        System.out.println(multiplier.multiply(10, 10.5));
+        System.out.println(multiplier.multiply(10.5, 10.5));
+        
+        Vehicle vehicle = new Vehicle();
+        System.out.println(vehicle.accelerate(100));
+        System.out.println(vehicle.run());
+        System.out.println(vehicle.stop());
+        
+        Vehicle car = new Car();
+        System.out.println(car.accelerate(80));
+        System.out.println(car.run());
+        System.out.println(car.stop());
+    }
+}

core-java/src/main/java/com/baeldung/methodoverloadingoverriding/model/Car.java

@@ -0,0 +1,9 @@
+package com.baeldung.methodoverloadingoverriding.model;
+
+public class Car extends Vehicle {
+
+    @Override
+    public String accelerate(long mph) {
+        return "The car accelerates at : " + mph + " MPH.";
+    }
+}

core-java/src/main/java/com/baeldung/methodoverloadingoverriding/model/Vehicle.java

@@ -0,0 +1,16 @@
+package com.baeldung.methodoverloadingoverriding.model;
+
+public class Vehicle {
+    
+    public String accelerate(long mph) {
+        return "The vehicle accelerates at : " + mph + " MPH.";
+    }
+    
+    public String stop() {
+        return "The vehicle has stopped.";
+    }
+    
+    public String run() {
+        return "The vehicle is running.";
+    }
+}

core-java/src/main/java/com/baeldung/methodoverloadingoverriding/util/Multiplier.java

@@ -0,0 +1,16 @@
+package com.baeldung.methodoverloadingoverriding.util;
+
+public class Multiplier {
+    
+    public int multiply(int a, int b) {
+        return a * b;
+    }
+    
+    public int multiply(int a, int b, int c) {
+        return a * b * c;
+    }
+    
+    public double multiply(double a, double b) {
+        return a * b;
+    }
+}