shivani chouhan ,bca ,2nd year
TRANSCRIPT
INFORMATION TECHNOLOGY
PROJECT REPORT
JAVA PROGRAMMING
TOPIC WRAPPER CLASS & NESTING OF METHOD
SUBMITTED BY:-
SHIVANI CHOUHAN BACHELORS OF COMPUTER APPLICATION
2ND YEAR
PROJECT REPORT
ON
JAVA PROGRAM
AT
DEZYNE E’COLE COLLEGE
AJMER
SUBMITTED TO
DEZYNE E’COLE COLLEGE
TOWARDS THE PARTIAL FULFILLMENT ON
BACHELOR’S OF COMPUTER APPLICATION
BY
SHIVANI CHOUHAN
DEZYNE E’COLE COLLEGE
106/10 CIVIL LINES AJMER
TEL. 0145-2624679
W.W.W.DEZYNEECOLE.COM
2016
ACKNOWLEDGMENT
I Shivani chouhan, student of Dezyne E’cole College, an
Extremely Grateful to each other 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 Constant Supervision as well as for
providing the necessary information and support
regarding the completion of project.
Thank you.
SYNOPSIS This project is a minor project mode, based on the
Theoretical concepts of java .This project made our basic
concepts on java strong.
P a g e | 1
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
also wrapper classes contained in the in the java lang. package .Following table
shows the simple data type and their corresponding wrapper classes types.
Wrapper classes for converting simple types .
Simple type Wrapper class
Boolean Boolean
Char Character
Integer Integer
Double Double
Float Float
converting primitive number 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(); Primitive long to long object
Converting object number 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 number to string using to string() method
Method calling Conversion action Str=Integer. to string(i); Primitive Integer to string Str=Float.to string(i); Primitive Float to string Str=Double.to string(i); Primitive Double to string Str=Long.to string(i); Primitive Long to string
P a g e | 2
Converting string objects to numeric objects using the static method value of()
Method calling Conversion action Double val=Double.value of (str); Converts string to Double object Float val=Float.value of (str); Converts string to Float object Int val=Integer.value of (str); Converts string to Integer object Long val=Long.value of (str); Converts string to Long object
Converting numeric string to primitive numbers using the 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
P a g e | 3
Output:-
P a g e | 4
Output:-
P a g e | 5
Output:-
P a g e | 6
Output:-
Output:-
P a g e | 7
Auto boxing and unboxing
The auto boxing and unboxing feature, introduced in J2Se 5.0, facilitates the
process of handling primitive data type in collection. We can use this feature to
converts primitive data types to wrapper class types automatically.the compiler
generates 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.double value();
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 restriction to perform the following conversion:-
1:-convert from null type to any primitive type.
2:-convert to the null type other than the identify conversion.
3:-convert from any class type c to any array type if c not object.
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
methods.
P a g e | 8
Programs 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.
Output:-
P a g e | 9
Another example of nesting of method
Output:-