Deepak Soni,BCA 2nd Year

2016

INFORMATION TECHNOLOGY

PROJECT REPORT

JAVA PROGRAMMING

TOPIC:

Wrapper classes & Nesting of methods

SUBMITTED BY:

Deepak soni

BCA

Dezyne E’cole College

www.dezyne e’cole college

G

http://www.dezyne/

pg. 1

Project Report

On

Java programming


Ajmer

Submitted to: Dezyne E’cole College

Toward the

Partial fulfillment on

Bachelors of computer application

By

Deepak soni


106/10, civil lines, Ajmer

Tele:-0145-2624679

www.dezyne E’cole College

2016-2017

http://www.dezyne/

pg. 2

Acknowledgment

I Deepak soni student of Dezyne E’cole College, an extremely

grateful to each and every individual who has contributed is

successful completion of my project.

I express my gratitude toward Dezyne E’cole College for their

guidance and constants supervision is well as for providing

the necessary information and support pergarding the

completion of project.

Thank You

pg. 3

SYMEPSIS

This project is a miner project made based on the theoretical

concepts of java. This project has made our basic concept on

java strong.

pg. 4

Wrapper Classes

As pointed out earlier, vector cannot handle primitive data type like int, float,

char, and double. Primitive data type may be converted into object type by using

the wrapper classes contained in java. Lang package. Following table shows the

simple data types and their corresponding wrapper class types.

Wrapper Classes For Converting Types

Simple Type Wrapper Class boolean Boolean

char Chararcter double Double

float Float Int Int

long Long

The wrapper classes have a number of unique methods for handling primitive

data type and objects. They are listed in the following tables.

Converting Primitive Number to object Number using

Constructor Method

Constructor Calling Conversion Action

Integer IntVal=new Integer(i); Primitive integer to Integer Object

float FloatVal=new Float(f); Primitive float to Float Object

Double DoubleVal=new Double(d); Primitive double to Double Object

Long Longval=new Long(); Primitive long to Long Object

pg. 5

Converting Object Number to Primitive Number using type

Value() Method

Converting Number to string Using to String() Method

Method Calling Conversion Action Str = Integer.toString(i); Primitive integer to string

Str = Float.toFloat(i); Primitive float to string Str=Double.to Double (i); Primitive double to string

Str=Long.toLong(i); Primitive long to string

Converting String Object to Number Object Using the Static

Method valueOf()

Method Calling Conversion Action DoubleVal=Double.valueOf(str); Converts string to Double object

FloatVal=Float.valueOf(str); Converts string to Float object IntegerVal=Integer.valueOf(str); Converts string to Integer object

LongVal=Long.valueOf(str); Converts string to Long object

Converting Numeric String to Primitive numbers Using Parsing

Methods

Method Calling Conversion Action

int i=Integer.ParseInt(str); Converts string to primitive integer double i=Double.ParseInt(str); Converts string to primitive double

Method Calling Conversion Action Int i=IntVal.intValue(); object to Primitive integer

Float f=FloatVal.floatValue(); object to Primitive float

Long l=LongVal.longValue(); object to Primitive long Double d=DoubleVal.doubleValue(); object to Primitive double

pg. 6

Converting primitive number to object number

OUTPUT::

pg. 7

Converting object number to primitive

OUTPUT:

pg. 8

Convert number to string

OUTPUT:

pg. 9

Converting string object to numeric object

Output:

pg. 10

Converting numeric string to primitive number

Output:

pg. 11

Autoboxing & Unboxing

The autoboxing and unboxing feature introduced in J2SE 5.0,facility the process

of handling primitive data type in collection.We can use this feature to convert

primityive data type to wrapper class types automatically.

The compiler genrates a code implicity to convert primitive type to the

corresponding wrapper class type and vice-versa.for Example consider the

following statement.

Double d=98.42;

Double db=a.doubleValue();

Using the autoboxing and unboxing featre we can rewrite the above code as::

Double d=98.42;

Double db1=a;

How,the java compiler produces restiction to following conversion

Convert from null type to any primitive type.

Convert to null to other than the identity

convert.

Convert from any class type c to any array type

if c is not object

pg. 12

Vector without using autoboxing & unboxing

OUTPUT:

pg. 13

EXAMPLE:

OUTPUT:

pg. 14

Nesting of method

We discussed earlier that a method of a class can be called only by an object (of

that class for class ifself, in the case of static methods)using the dot

operator.However , there is an exception to this.it method can be called by using

only its name by another method of same class.This is know as nesting of

methods.

Program illstrates the nesting of methods inside a class.the class nesting defines

one constructor and two methods,namely largest() and display calls the method

largest of the method largest() to determine the largest of the two number and

then dislay the result.

pg. 15

Nesting of class

Output:

pg. 16

Example

Output:

pg. 17

THANKING

YOU

Technology

Deepak Soni,BCA 2nd Year