Write a java program to demonstrate the package concept using a simple example.

Write a java program to demonstrate the package concept using a simple example.

Program Algorithm:

STEP 1: Create a package of user-defined.

STEP 2: Create a class of specific user-defined and save them in the package folder created.

STEP 3: All the classes are saved in a separate file and used in a package folder just by importing them.

STEP 4: The members and methods and class defined as protected specifier can be accessed throughout the package.

Program Code:

File name: Check.java

package rear;

public class Check

{

int n=1;

private int np=2;

protected int npro=3;

public int npub=4;

public Check()

{

System.out.println("Base constructor:");

System.out.println("default n:"+n);

System.out.println("private n(np):"+np);

System.out.println("protected n(npro):"+npro);

System.out.println("public n(npub):"+npub);

System.out.println(" ");

}

}

File name: DerSame.java

package rear;

class DerSame extends Check

{

DerSame()

{

System.out.println("Derived Constructor");

System.out.println("n:"+n);

System.out.println("npro:"+npro);

System.out.println("npub:"+npub);

System.out.println(" ");

}

}

File name: Create.java

package rear;

class Create

{

public static void main(String args[])

{

DerSame d=new DerSame()

}

}

File name: DerAno.java

package Front;

import rear.Check;

class DerAno

{

public static void main(String args[])

{

System.out.println("Importing class Constructor");

Check c=new Check();

System.out.println("npub:"+c.npub);

System.out.println(" ");

}

}

Sample Inputs and Outputs:

Running Create.class

Base constructor:

default n:1

private n(np):2

protected n(npro):3

public n(npub):4

Derived Constructor

n:1

npro:3

npub:4

Running DerAno.class

Importing class Constructor

Base constructor:

default n:1

private n(np):2

protected n(npro):3

public n(npub):4

npub:4