student Dezyne E'cole College, www.dezyneecole.com

1. INORMATION TECHNOLOGY
Project Report
Java Programming
TOPIC
Wrapper Class and Nesting Method
Submitted by
Daksh Sharma
Bachelor of computer application
Dezyne E’cole College
www.dezyneecole.com

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Project Report
On
Java programming
At
Dezyne Ecole College
Towards the
Partial fulfillment of
Bachelor of computer application
By
Daksh Sharma
Dezyne E’cole College
106/10, civil lines, Ajmer
Tel- 0145-262479
www.dezyneecole.com
2016

3. ACKNOWLEDGEMENT
I Daksh Sharma, student of Dezyne E’cole College,
an extremely grateful to each and every individual
who has contribute in successful completion 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.

4. SYNOPSIS
This project is a minor project made based on
the theoretical concepts of java this project has
made our base concepts 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 types may be converted into object types by using the wrapper classes contained
in the java.lang package. Following table shows the simple data types and their corresponding
wrapper class types.
Wrapper Classes for Converting Types
Simple Types Wrapper Class
Boolean Boolean
Char Character
Double Double
Float Float
Int Integer
Long Long
The Wrapper class 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 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(l); Primitive long to Long Object
Converting Object Numbers to Primitive Numbers Using typeValue()
Method
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
Converting Numbers to String Using toString() Method
Method Calling Conversion Action

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Str=Integer.toString(i); Primitive integer to string
Str=Float.toString(f); Primitive float to string
Str=Double.toString(d); Primitive double to string
Str=Long.toString(l); Primitive long to string
Converting String Objects to Numeric Objects 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
IntVal=Int.ValueOf(str); Converts string to Int 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
Long l=Long.parseInt(str) Converts String to Primitive Integer
//Converting Primitive Numbers to Object Numbers

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//Converting Object Numbers to Primitive Numbers

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//Converting Numbers to String
//Converting String Object to Numeric Object

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//Converting Numeric String to Primitive Numbers

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Autoboxing and Unboxing
The Autoboxing and Unboxing feature, introduced in J2SE 5.0, facilitates 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 implicitly to convert
primitive data types to the corresponding wrapper class type and vice versa.
For example, consider the following statement
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 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 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 display the result.

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