Page 465 - Cs_withBlue_J_C11_Flipbook
P. 465
C. Answer the following questions:
1. What is the difference between a class and a package.
Ans. Class Package
A class is a blueprint or prototype of similar objects. A package is a namespace under which you can categorise
classes.
2. Differentiate between package and import keyword.
Ans. Package Import
Package is used to put all related modules into one Import is used to include the specific class in a particular
common folder for a better understanding. package that we need to run our application.
3. Differentiate between public and default access in class.
Ans. Public Default
Data members, member methods, and blocks declared Data Members, member methods, and blocks declared
inside a public class can be accessed from any class. inside a default class is available to any other class in the
same package.
The access specifier public must be written. The access specifier is not written.
4. Differentiate between user-defined package and built-in package.
Ans.
Built-in packages User-defined packages
The packages that are already defined in Java software are The packages that are created by the programmer are
known as built-in packages. known as user-defined packages.
5. Differentiate between JDK and API.
Ans.
JDK API
Java Development Kit is a software development Java Application Programming Interface (API) gives us the
environment used for developing Java applications and list of all the packages, classes, interfaces along with their
applets. fields and methods.
It includes the Java Runtime Environment (JRE), an It contains classes and packages, which are helpful in
interpreter/loader (Java), a compiler (javac), an archiver minimising and simplifying Java coding like java.lang, java.
(jar), a documentation generator (Javadoc) and API. util, java.io, etc.
6. Write a program to create a package Eleven containing class AreaC having the following specifications:
Package : Eleven
Class name : AreaC
Data Members
double radius : Store radius of a circle
Member Methods
AreaC(double r) : Constructor to assign the data members
double calarea() : Calculates and returns the area of a circle using the formula A = πr
2
Write a second class Shape in package Orange_prog to import class AreaC of package Eleven and use the method calarea() to
calculate the volume of cone and cylinder. The class description is given below.
Package : Orange_prog
Class name : Shape
Data Members
double height, vol : Stores height and vol
Member Methods
void conevol() : Accepts height and calculates the volume of a cone using the formula πr h/3
2
2
void cylindervol() : Accepts height and calculates the volume of a cylinder using the formula πr h
Ans. package Eleven;
public class AreaC
463
Packages 463

