brijesh peswani,bca 2nd year
TRANSCRIPT
ROJECT EPORT
JAVA PROGRAMMING
TOPIC
Wrapper Class and
Nesting Method
Submitted by
Brijesh peswani
BCA -II Year Dezyne E’cole College
www.dezyneecole.com
INFORMATION TECHNOLOGY
Project report
On
Java program
At
Dezyne E’cole college
Ajmer
Submitted to
Dezyne E’cole college
Towards The
Partial Fulfillment on
BCA – II year
(Bachelor of computer application)
By
Brijesh peswani
Dezyne e’cole college
106/10,civil lines,ajmer
Tel-0145-2624679
www.dezyneecole.com
AKNOWLEDGEMENT
I Brijesh Peswani Student Of Dezyne e’cole College An Extremely Grateful To Each And Every
Individual Who Has Contributed In Success Full Compaction 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.
Thank You.
Synopsis This project is a minor project made, based on the theoretical concept of java. This project has
made our basic concept of java strong.
Wrapper classes: As pointed out earlier vector 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 language package following table show the simple data types and their
corresponding wrapper class type..
Wrapper class for converting types:--
Simple types Wrapper class Boolean Boolean
Char Char Double Double Float Float Int Int
Long Long
The wrapper classes have a number of unique methods for handling primitive data types and object.
they are listed in following table.
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(i); Primitive float to float object
Double doubleval=newdouble(d); Primitive double to double object Long long val=newlong(i); Primitive long to long object
Converting object number to primitive number using types value ()method
Method calling Conversion action Int i=intval intvalue(); Object to primitive integer Float f=floatval..float value(); Object to primitive float Long i=long val.longvalue(); Object to primitive long Double d=doubleval.double(); Object to primitive double
Converting number string to using string() method:-
Converting string objects to number object 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=integer.valueOf(str); Converts string to integer object longVal=long.valueOf(str); Converts string to long object
Converting number string to primitive number using parsing methods:-
Int i=integer.parseInt(str); Converts string to Primitive integer Float f=float.parseInt(str); Converts string to Primitive float Long f=long.parseInt(str); Converts string to Primitive long Doublef f=double.parseInt(str); Converts string to Primitive double
Method calling Conversion action Str-integer.toString(i); Primitive string to integer
Str-float.toFloat(f); Primitive float to string
Str-double.toDouble(d); Primitive double to string
Str-long.toLong(i); Primitive long to string
Converting primitive numbers to object numbers:-
output
converting object number to primitive number:-
Converting numeric string to primitive number:-
Autoboxing and unboxing
The autoboxing and unboxing feature,introduce in jase 5.0,features the process of handling primitive
data types in collection .we can use this feature to convert 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 …for example::=
Consider the following:-
Double a=98.42;
Double dbl=a.doublevalue();
Using the autoboxing and unboxing feature,we can return:
Double d=98.42
Double dbl=a;
How the java compiler provides restrictionms perform the following
conversion:
1.Convert from null type to any primitive type..
2.Convert to the null type other the identity conversion..
3.Convert from any class type a to any array if it is not object..
Vector without using autoboxing &unboxing:_
*Vector with using autobxing and unboxing:-
Nesting of method:- We discussed earlier that a method of a class can be called only by an object of that class for class ,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 name by
another method of some 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….
A method can call any number of methods .it is also possible for a called method to call another method.
This is method 1 may called method 2 which in turn may call methods…