Overloading in Java

Different ways to overload the method

There are two ways to overload the method in java

• By changing number of arguments ``` class Adder{
  static int add(int a,int b){return a+b;}
  static int add(int a,int b,int c){return a+b+c;}
  }
  class TestOverloading1{
  public static void main(String[] args){
  System.out.println(Adder.add(11,11));
  System.out.println(Adder.add(11,11,11));
  }}

Output: 22 33

- By changing the data type

class Adder{
static int add(int a, int b){return a+b;}
static double add(double a, double b){return a+b;}
}
class TestOverloading2{
public static void main(String[] args){
System.out.println(Adder.add(11,11));
System.out.println(Adder.add(12.3,12.6));
}}

Output: 22 24.9

### Overriding in Java
If subclass (child class) has the same method as declared in the parent class, it is known as method overriding in Java.

##### Rules for Java Method Overriding
- The method must have the same name as in the parent class
- The method must have the same parameter as in the parent class.
- There must be an IS-A relationship (inheritance).

class Vehicle{
//defining a method
void run(){System.out.println(“Vehicle is running”);}
}
//Creating a child class
class Bike2 extends Vehicle{
//defining the same method as in the parent class
void run(){System.out.println(“Bike is running safely”);}

public static void main(String args[]){
Bike2 obj = new Bike2();//creating object
obj.run();//calling method
}
}

Output: Bike is running safely ```

Understanding all java access modifiers

Access Modifier	within class	within package	outside package by subclass only	outside package
Private	Y	N	N	N
Default	Y	Y	N	N
Protected	Y	Y	Y	N
Public	Y	Y	Y	Y