kirti kumawat
TRANSCRIPT
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
1
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
2
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
3
SYNOPSIS
This Project Is A Minor Project Made Based On Theoretical
Concepts Of Java. This Project Has Made Our Basic Concepts On
Java Strong.
4
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
5
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
6
CONVERTING PRIMITIVE NUMBERS TO OBJECT NUMBER
7
CONVERTING OBJECT NUMBER TO PRIMITIVE NUMBER
8
CONVERTING NUMBER TO STRING
9
CONVERTING STRING OBJECTS TO NUMBERIC OBJECTS
10
CONVERTING NUMERIC STRING TO PRIMITIVE NUMBER
11
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
12
VECTOR WITH USING AUTOBOXING AND UNBOXING
13
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
14
ANOTHER EXAMPLE OF NESTING OF METHODS
15
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.
16
THANK YOU