This document is a project report submitted by Kaushal Soni towards their BCA degree at Dezyne E'cole College. It discusses wrapper classes in Java, which allow primitive data types to be handled as objects, and nesting of methods, where one method calls another method in the same class. The report provides examples of converting between primitive types and wrapper classes, calling methods within a class, and using wrapper classes and autoboxing/unboxing features with collections like vectors.

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INFORMATION TECHNOLOGY
JAVA PROGRAMME
TOPIC
Wrapper Class And
Nesting Method
SUBMITTED BY
Kaushal Soni
BCA-IInd
Year
Dezyne E’cole College
www.dezyneecole.com

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Project Report
On
Java Programme
At
Dezyne E’cole College
Ajmer
Submitted To
Dezyne E’cole College
Towards The
Partial Fulfillment
BCA
(Bachelor Of Computer Application)
By
Kaushal Soni
Dezyne E’Cole College
106/10, Civil Lines, Ajmer
Tel.0145-2624679
www.dezyneecole.com
2016-2017

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ACKNOWLEDGEMENT
I Am Kaushal Soni, Student Of Dezyne E’Cole College, 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 type types like int, float,
char and double. Primitive data types may be converted into object types by using
the wrapper classes contained in the java. 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 Character
Double Double
Float Float
Int Integer
Long Long
The wrapper classes have a number of unique methods for handling primitive data
types and object. They are listed in the following tables.
Converting primitive numbers to object number using constructor method
Constructor calling Conversion action
Integer IntVal=new Integer() 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.
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=integertostring(); Primitive integer to string
Str=floattofloat(); Primitive float to string
Str=DoubletoDouble(); Primitive double to string
str=Long toLong(); Primitive long to string

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Converting String Objects To Numbers Objects Using The Static Method
valueOff()
Method calling Conversion
Double val=Double valueOff(str); Converts string to Double objects.
Float val=Float valueOff(str); Converts string to Float objects.
Int val=Integer valueOff(str); Converts string to Integer objects.
Long val=Long valueOff(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.
float f=Float.parseFloat(str); Converts string to primitive float.

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Converting Primitive Number To Object Number

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Converting Object Number To Primitive Number

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Convert Number To String

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Converting String Object To Numeric Object

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Converting Numeric String To Primitive Number

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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 the this feature to convert
primitive data types to wrapper class types automatically. The compiler generates a
code implicitly to convert primitive types to the corresponding wrapper class type and
vice versa. For example, consider the following statements:
Double d_object= 98.42;
Double d_primitive=d_object;
Using the autoboxing and unboxing feature, we can rewrite the above code as:
Double d_object= 98.42;
Double d_primitive= d_object;
How, the java compiler provides restrictions to perform the following conversions:
1. Convert from null type to any primitive type.
2. 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 Autoboxing And Unboxing

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Vector With Using Autoboxing And Unboxing

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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 illustrated the nesting of method 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 display the result.

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Nesting Of Methods

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Nesting Of Methods

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A method can called any number of method. It is also possible for a called method1
to call another. This is method1 may call method2, which in turn may call method3.

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Thank You