Kirti Kumawat

INFORMATION TECHNOLOGY

PROJECT REPORT

JAVA PROGRAMMING

TOPIC

WRAPPER CLASSES AND

NESTED OF METHOD

SUMMITED BY

KIRTI KUMAWAT

BCA II YEAR

DEZYNE E’COLE COLLEGE

WWW.DEZYNECOLE.COM

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PARTIAL FULFILLMENT

ON

JAVA PROGRAMMING

AT

DEZYNE E’COLE COLLEGE

SUBMITTED TO

DEZYNE E’COLE COLLEGE

PARTIAL FULFILLMENT ON

BCA

BACHELORS OF COMPUTER APPLICATION

BY

KIRTI KUMAWAT

DEZYNE E’COLE COLLEGE

106/10,CIVIL LINES AJMER

TEL - 0145-2624679

WWW.DEZYNEECOLE.COM

2016-2017

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ACKNOWLEDGEMENT

I Kirti Kumawat Student Of Dezyne E’cole College, An

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 To

Their Guidelines And Constant Supervision As Well For

Providing The Necessary Information And Support

Regarding The Completion Of Project.

Thank You

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SYNOPSIS

This Project Is A Minor Project Made Based On Theoretical

Concepts Of Java. This Project Has Made Our Basic Concepts On

Java Strong.

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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 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 MEMBER OF UNIQUE METHODS FOR HANDLING PRIMITIVE

DATA TYPE AND OBJECTS. THEY ARE LISTED IN THE FOLLOWING TABLES.

CONSTRUCTOR 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=NEWLONG(L); PRIMITIVE LONG TO LONG OBJECT

CONVERTING OBJECT NUMBERS TO PRIMITIVE NUMBER USING TYPE

VALUE()METHOD

METHOD CALLING CONVERSION ACTION INT I=INTVAL INTVALUE(); OBJECT TO PRIMITIVE INTEGER

FLOAT F=FLOAT VAL.FLOATVALUE(); OBJECT TO PRIMITIVE FLOAT

LONG L=LONGVAL.LONGVALUE(); OBJECT TO PRIMITIVE LONG

DOUBLE=DOUBLEVAL.DOUBLEVALUE(); OBJECT TO PRIMITIVE DOUBLE

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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

STR=DOUBLE TODOUBLE(D); PRIMITIVE DOUBLE TO STRING

STR=LONG TOLONG(L); PRIMITIVE LONG TO STRING

CONVERTING STRING OBJECTS TO NUMBERS OBJECTS USING THE STATIC

METHOD VALUEOF()

METHOD CALLING CONVERSION ACTION DOUBLEVAL=DOUBLE.VALUEOFF(STR); CONVERTS STRING TO DOUBLE OBJECT

FLOATVAL=FLOAT.VALUEOFF(STR); CONVERTS STRING TO FLOAT OBJECT

INTVAL=INTEGER.VALUEOFF(STR); CONVERTS STRING TO INTEGER OBJECT

LONGVAL=LONG.VALUEOFF(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

FLOAT F =FLOAT PARSEFLOAT(STR); CONVERTS STRING TO PRIMITIVE FLOAT

LONG L=LONG PARSELONG(STR); CONVERTS STRING TO PRIMITIVE LONG

DOUBLE D =DOUBLE PARSEDOUBLE(STR); CONVERTS STRING TO PRIMITIVE DOUBLE

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CONVERTING PRIMITIVE NUMBERS TO OBJECT NUMBER

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CONVERTING OBJECT NUMBER TO PRIMITIVE NUMBER

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CONVERTING NUMBER TO STRING

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CONVERTING STRING OBJECTS TO NUMBERIC OBJECTS

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CONVERTING NUMERIC STRING TO PRIMITIVE NUMBER

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AUTO BOXING AND UNBOXING

THE AUTOBOXING AND UNBOXING FEATURES,INTRODUCED IN J2SE5.0 FACILITATES THE

PROCESS OF HANDING PRIMITIVE DATA TYPE IN COLLECTIONS.WE CAN USE THIS FEATURES TO

CONVERT PRIMITIVE DATA TYPE TO WRAPPER CLASS TYPES AUTOMATICALLY.THE COMPILER

GENERATES THE CODE IMPLICITLY TO CONVERT PRIMITIVE TYPE TO CORRESPONDING

WRAPPER CLASS TYPE AND VICE-VERSA.FOR EXAMPLE ,CONSIDER THE FOLLOWING

STATEMENT.

DOUBLE D_OBJECT =97.77;

DOUBLE D_PRIMITIVE=D_OBJECT.DOUBLEVALUE();

USING THE AUTOBOXING AND UNBOXING FEATURE,WE CAN REWRITE THE ABOVE CODE AS:

DOUBLE D_OBJECT =97.77;

DOUBLE D_PRIMITIVE=D_OBJECT;

HOW,THE JAVA COMPILER PROVIDES RESTRICTIONS TO PERFORM THE FOLLOWING

CONVERSIONS:

CONVERT FORM 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.

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 ,THIS IS AN EXCEPTION TO THIS.A METHOD CAN BE CALLED BY USING

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 DISPLAYS THE RESULT.

NESTING OF METHODS

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ANOTHER EXAMPLE OF NESTING OF METHODS

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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 METHOD 2,WHICH IN TURN MAY

CALL METHOD 3.

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THANK YOU