Karishma Dhanwani,BCA 2nd Year

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INFORMATION TECHNOLOGY

PROJECT REPORT JAVA PROGRAMMING

TOPIC

Wrapper class and Nesting

Method

Submitted by- Karishma Dhanwani

BCA-Bechlor of Computer Application || year

Dezyne E’cole College, www.dezynee’cole.com

http://www.dezynee'cole.com/

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Project Report On

Java Program

At

Dezyne E’cole College

Ajmer

Submitted To


Towards The

Partial Fullfillment on

BCA

Bachlores Of Computer Application

By

Karishma Dhanwani


106/10 Civil Lines, Ajmer

Tel-0145-2624679

www.dezyne e’cole.com

2016-2017

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ACKNOWLEDGEMENT I Karishma Dhanwani, Student Of Dezyne E’cole College, An Extremelly

Grantefull To Each And Every Individual Who Has Contiributed In Successful

Comletion Of My Project. I Express My Gratitude Towards Dezyne E’cole

College For Their Guidance And Constant Supervision As Well As For Providing

The Necessary Information And Support Regarding The Completion Of Project.

Thank You.

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Synopsis This Project is a Minar Project Made, Based On The Theoretical Concepts of

Java This Project Has Made our Basic Cocepts On Java Strong.

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Wrapper class :

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 packages. Following table shows the simple data types and their corresponding wrapper class

types.

Simlpe 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 handeling primitive data type and object.

They are listed in the following tables.

Converting Primitive Numbers to Object Number Using Constructor Method

Constructor Calling Converting 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(l); Primitive long to Long Object

Converting Object Number to Primitive Number Using Type Value() Method

Method Calling Conversion Action

int i=IntVal.intValue(); Object to Primitive integer

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

Long l=Long.longValue(); Object to Primitive long

Double d=DoubleVal.doubleValue(); Object to Primitive Double

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Converting Number to String Using to String() Method


Str=Integer.toString(i); Primitive integer to string

Str=Float.toFloat(f); Primitive float to string

Str=Double.toDouble(d); Primitive double to string

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

Converting String Object to Number Using the Static Method value of()


DoubleVal = Double.ValueOf(str); Converting string to Double object

FloatVal = Float.ValueOf(str); Converting string to float object

Integer = Integer.ValueOf(str); Converting string to Integer object

LongVal = Long.ValueOf(str); Converting string to Long object

Converting Numeric String to Primitive Number Using Parseing Method


Int l = Integer.ParseInt(str); Converting string to primitive integer

float f = Float.ParseFloat(str); Converting string to primitive float

long l = Long.ParseLong(str); Converting string to primitive Long

double d = Double.ParseDouble(str); Converting string to primitive double

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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, Facilitates the process of handeling

primitive data type in collectings. We can use this feature to convert primitive data types to wrapper

class types automatically.

The compiler generates a code implicitly to convert primitive type to the corresponding

wrapper class type and vice-versa. For example consider the following statement:-

Double d = 98.42;

Double dbl = a.double value();

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 conversion:

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 id C is not object.

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Vector without using Autoboxing and Unboxing

Output:-

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Vector with Autoboxing and Unboxing

Output:-

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Nesting of Methods:-

We dicussed 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 method

can be called by using only its name by another method of the same class. This is known a Nesting of

Methods.

Prongram illustrates 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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Another program of Nesting

Output:-

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

a called method to call another method. That is, method1 may call method2, which in turn may call

methods.

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Thank you…

Technology

Karishma Dhanwani,BCA 2nd Year