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

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INFORMATION TECHNOLOGY
PROJECT REPORT
JAVA PROGRAMMING
TOPIC
Wrapper class and
Nesting of Method
SUBMITTED BY
Varun Kaushik
BCA IInd
Dezyne E’cole College
www.dezyneecole.com

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Project Report
On Java Programming
At
Dezyne E’cole College
Ajmer
Submitted to
Dezyne E’cole College
Towards the
Partial fulfillment on
Bachelor computer application
By
Varun Kaushik
Dezyne E’cole College
106/10, Civil lines, Ajmer
Tel:-0145-2624679
www.dezyneecole.com
2016-2017

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ACKNOWLEDGMENT
I Varun Kaushik, 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
for their. Guidance and Constant super vision as well as
for providing the necessary information and support
regarding the completion of project.

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SYNOPSIS
This project is a minar project made, based on the
theoretical concepts of Java this project has made our
basic concepts on Java storng.

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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 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 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(l); Primitive long to Long Object
Converting Object Numbers to Primitive Number Using typeValue()
Method
Method Calling Conversion Action
int i=IntVal.intValue(); Object to Primitive integer
float f=FloatVal.floatValue(); Object to Primitive float
long l=LongVal.longValue(); Object to Primitive long

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double d=DoubleVal.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
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.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 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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1. Converting Primitive Numbers to Object Number
Output

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2. Converting Object Numbers to Primitive Numbers
Output:-

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3. Converting Numbers to String
Output:-

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4. Converting string object to numeric object :-
Output :-

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5. Converting numeric string to primitive number :-
Output :-

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AutoBoxing and unboxing:-
The autoboxing and unboxing feature, introduced in j2se 5.0,
facilitates 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 generates a code implicity
To convert type to the corresponding wrapper alss type and vice
versa. For example , consider the following statements:
Double d_object =98.42;
double d_primitive=d_object;
Using the autoboxing and unboxing feature, we can rewrite the above
code as:
Double d_object =98.42;
double d_primitive=d_object;
How , the java compiler provides restriction to perform the following
conversions:
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 is not object.

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6. Vector without using autoboxing and unboxing:-
Output :-

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7. Vector with using autoboxing and unboxing:-
Output:-

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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 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.
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.
1.Nesting of Methods:-
Output:-
2.Another program of nesting of methods:-

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Output:-
Amethod can call any number of methods. It is also possible for a
called methods to call anther method. That is , method1 may call
b ,which in trun may call method3.

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Thank you