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Project Report

Java Programme

Submitted By:

Rakesh Bijawat

BCA

Dezyne E’cole College

www.dezyneecole.com

Topic:

Wrapper Class and

Nesting Methods.

INFORMATION

TECHNOLOGY

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Project Report

On

Java Program

At

Dezyne E’cole College

Ajmer

Submitted To

Dezyne E’cole College

Towards The

Partial Fulfillment

BCA

(Bachelors of Computer Applications)

By

Rakesh Bijawat

Dezyne E’Cole College

106/10, Civil Lines, Ajmer

Tel.0145-2624679

www.dezyneecole.com

2016-2017

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ACKNOWLEDGEMENT

I Am Rakesh Bijawat, Student Of Dezyne E’cole College, And Am

Extremely Grateful To Each And Every Individual Who Has Contributed

In Successful Completion Of My Project. I Express My Gratitude

Towards Dezyne E’cole College For Their Guidance And Constants

Supervision As Well As For Providing The Necessary Information And

Support Regarding The Completion Of Project.

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SYNOPSIS

This Project Is a Miner Project Made Based on the Theatrical Concepts

of JAVA .This Project Has Made Our Basic Concept on JAVA Strong.

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Wrapper Classes:

As pointed out earlier, vectors cannot handle primitive data types like

int, float, char, and double. Primitive data type may be converted into

object types by using the wrapper classes contained in the java.lang

Package. Following table shows the simple data type and their

corresponding wrapper class type.

Wrapper classes for converting simple Types

Simple Type Wrapper Class

Boolean Boolean

Char Character

Double Double

Float Float

Int Integer

Long Long

The wrapper classes have a number of unique methods for handling

primitive data types and objects. They are listed in the following

tables.

Converting Primitive Numbers to object Numbers using Constructor

methods

Constructor Calling Conversion action

Integer Interval=new Integer(i); Primitive integer to Integer object

Float FloatVal=new float(); Primitive float to Float object.

Double DoubleVal=new double(d); Primitive double to Double object.

Long LongVal=new long(l); Primitive long to Long object.

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Converting object numbers to primitive number using type value ()

method

Method calling Conversion action

Int i=IntVal.int value(); Object to primitive integer

float f=FloatVal.float value(); Object to primitive float

Long l=LongVal.long value(); Object to primitive long

Double d=DoubleVal.double value();

Object to primitive double

Converting numbers to string using to String () method

Method calling Conversion action

Str=Integer.toString(); Primitive integer to String Str=Float.toFloat(); Primitive float to String

Str=Double.toDouble(); Primitive double to String

Str=Long.toLong(); Primitive long to String

Converting String objects to numbers objects using the static method

value Of ()

Method calling Conversion

DoubleVal=Double.ValueOf(Str); Converts string to Double objects. FloatVal=Float.ValueOf(Str); Converts string to Float objects.

IntVal=Integer.ValueOf(Str); Converts string to Integer objects.

LongVal=Long.ValueOf(Str); Converts string to Long objects.

Converting numeric string to primitive numbers using parsing

methods

Method calling Conversion action

Int i=Integer.parseInt(Str); Converts string to primitive integer.

long l=Long.parseLong(Str); Converts string to primitive long.

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Converting Primitive Numbers to Object Numbers.

Output:-

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Converting object Numbers to Primitive Numbers.

Output:-

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Converting Numbers to String

Output:-

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Converting String Object to Numeric Object.

Output:-

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Converting Numeric String to Primitive Numbers.

Output:-

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Auto boxing and Unboxing

The auto boxing and unboxing feature, introduced in J2SE 5.0, facilities

the process of handling primitive data types in collections. We can use

this feature to convert primitive data types to wrapper class types

automatically. The compiler generates a code implicity to convert

primitive types to the corresponding wrapper class type and vice

versa.

For example:-

Consider the following statements:

Double d=98.42;

Double dbl=d.doubleValue ();

Using the auto boxing and unboxing feature, we can rewrite the above

code as:-

Double d= 98.42;

Double dbl= d;

How the java compiler provides restrictions to perform the following

conversions:-

Convert from null type to any primitive type.

Convert to the null type other than the identify conversion.

Convert from any class type C to any array type if C is not object.

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Vector without using auto boxing and unboxing

Output:-

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Vector with using auto boxing and unboxing

Output:-

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Nesting of methods

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

object of that class (or class itself, in the case of static methods) using

the dot (.) operator. However, there is an exception to this. A method

can be called by using only its name by another method of the same

class. This is known as nesting of methods.

Program illustrations the nesting of methods inside a class. The class

Nesting defines one constructor and two methods, namely largest ()

and display (). The method display () calls the method largest () to

determine the largest of the two numbers and then displays the

result.

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Nesting of methods

Output:-

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Nesting of methods

Output:-

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A method can call any number of methods. It also possible for a called

method to call another method. That is, method1 may call method2,

which in turn may call method3.

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Thank You