Java Programming Practical 10
Question 1
Write a program to implement user defined packages in terms of creating a new package and importing the same.
PkgClass.java
Java
package pkg1;
public class PkgClass
{
public void show()
{
System.out.println("This is inside package");
}
public static int subtract(int a, int b)
{
return a - b;
}
}
Save this file as PkgClass.java inside folder pkg1
PkgMain.java
Java
import pkg1.PkgClass;
public class PkgMain
{
public static void main(String[] args)
{
PkgClass obj=new PkgClass();
obj.show();
}
}
Compile this file which will automatically compile class inside package pkg1. After that run this class.
Output
Question 2
Define a package named myInstitute include class named as department with one method to display the staff of that department. Develop a program to import this package in a java application and call the method defined in the package.
Department.java
Java
package myInstitute;
public class Department
{
public void displayStaff()
{
System.out.println("Staff of the department:");
System.out.println("HOD: ABC");
System.out.println("Lecturer: PQR");
System.out.println("Lab Assistant: XYZ");
}
}
Save this file as Department.java inside folder myInstitute.
PackageDemo.java
Java
import myInstitute.Department;
public class PackageDemo
{
public static void main(String[] args)
{
Department cs = new Department();
cs.displayStaff();
}
}
Compile this file which will automatically compile class inside package myInstitute. After that run this class.
Output
Question 3
Develop a program which consists of the package named let_me_calculate with a class named Calculator and a method named add to add two integer numbers. Import let_me_calculate package in another program (class named Demo) to add two numbers.
Calculator.java
Java
package let_me_calculate;
public class Calculator
{
public void add(int a, int b)
{
int sum = a + b;
System.out.println("Addition is :"+sum);
}
}
Save this file as Calculator.java inside folder let_me_calculate.
Demo.java
Java
import let_me_calculate.Calculator;
public class Demo
{
public static void main(String[] args)
{
Calculator c = new Calculator();
c.add(20, 30);
}
}
Compile this file which will automatically compile class inside package let_me_calculate. After that run this class.
Output
