Student Dezyne E'cole College, www.dezyneecole.com Project on Wrapper Class and Nesting Method in Java

1. INFORMATION TECHNOLOGY
PROJECT REPORT
JAVA PROGRAMMING
TOPIC
Wrapper class and
nesting of method
SUBMITTED BY
Ronak kachhawa
Bachelors of Computer Application
BCA IInd YEAR
Dezyne E,cole college
www.dezyneecole.com
2016-2017
R

2. Project Report
On
Java programming
At
Dezyne E’cole College
Ajmer
Submitted to
Dezyne E’cole College
Towards The
Partial Fulfillment on
Bachelors of Computer Application
BCA IInd Year
By
Ronak kachhawa
Dezyne E’cole College
106/10, civil lines, Ajmer
Tel:-0145-2624679
www.dezyneecole.com
2016-2017
R

3. Acknowledgment
I Ronak Kachhawa ,Student Of Dezyne E’cole College, An Exteremely Greatfull
To Each And Evey Individual Who Has Contributed 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 Minar Project Mode, Based On The Theorepical Concepts Of
Java This Project Has Made Our Basic Concepts On Java Strong.

5. 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
pakage. 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 type 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 Objects
Float FloatVal=new Float(f); Primitive float to Float Objects
Double DoubleVal=new Double(d); Primitive double to Double Objects
Long LongVal=new long(l); Primitive long to Long Object
 Converting Object Number To Primitive Number Using Typevalue() Method
Method Calling Conversion Action
Int I=Int val.intValue(); Object to primitive integer
float f=Float val.floatValue(); Object to primitive float
long l=Long val.longValue(); Object to primitive long
double d=Double val.doubleValue(); Object to primitive double
 Converting Numbers To String Using To String() Method
Method Calling Conversion Action
str=Integer.toString(i); Primitive integer to string
str=Float.toFloat(f); Primitive float to string

6. str=Double.toDouble(d); Primitive double to string
str=Long.toLong(l); Primitive long to string
 Converting String Objects To Number Objects Using The Static Method Valueof()
Method Calling Conversion Action
DoubleVal=Double.valueOf(str); Convert string to Double object
FloatVal=Float.valueOf(str); Convert string to Float object
IntVal=Integer.valueOf(str); Convert string to Integer object
LongVal=Long.valueOf(str); Convert string to Long object
 Converting Numeric String To Primitive Numbers Using Parsing Methods
Method Calling Conversion Action
Int i=Integer.parseInt(str); Convert string to primitive integer
Float f=Float.parseFloat(str); Convert string to primitive float
Long l=Long.parseLong(str); Convert string to primitive long
Double d=Double.parseDouble(str); Convert string to primitive double

7.  Converting Primitive Numbers To Object Numbers

8.  Converting Object Numbers To Primitive Numbers

9.  Converting Numbers To String

10.  Converting String Object To Numeric Object

11.  Converting Numeric String To Primitive Numbers

12. Autoboxing And Unboxing
The autoboxing 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 genrates a code implicity to convert primitive type 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 Autoboxing 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 As:-
 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

13.  Vector Without Using Autoboxing & Unboxing

14.  Vector With Using Autoboxing & Unboxing

15. Nesting Of Method
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 method) 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 method.
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 displays the result.
Example:- Nesting Of Methods

16.  Another Program Of Nesting Of Method
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 Method

17. Thank you