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

1. BACHELOR OF COMPUTER APPLICATION
Dezyne E’cole College
JAVA PROGRAMMIG
TOPIC: WRAPPER CLASSES & NESTING OF METHOD
INFORMATION TECHNOLOGY
Shaikh Mohammad Usman haider
R
Submitted By

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Project Report
On
Java Program
At
Dezyne E’cole College
Ajmer
Submitted To
Dezyne E’cole College
Toward The
Practical Fulfillment On
BCA
By
Usman haider
Dezyne E’cole College
106/10, Civil Line Lines, Ajmer
Tel – 0145- 2624679
www.dezyneecole.com
2016-2017
R

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ACKNOWLEDGMENT
I Shaikh Mohammad Usman Haider, Student of Dezyne E’cole College,
an Externally Grateful To Each And Every Individual Who Has Contribute
In Successful Completion of My Project
I Express My Gratitude Towards Dezyne E’cole College For 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 The Theoretical Concept
Of JAVA This Project Has Made Our Basic Concepts Of 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 type 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 method for handling primitive
data types and object. They are listed in the following table.
Converting Primitive Number to Object Number using Constructor Method
Converting Object Number to Primitive Number using typeValue() Method
Constructor Calling Conversion Action
Integer IntVal=new Integer(i); Primitive integer to integer Object
Float floatVal=new flaot(f); Primitive float to float Object
Double DoubleVal=new Double(d); Primitive Double to Double Object
Long lonfgVal=new Long(l); Primitive Long to long Object
Method Calling Conversion Action
int i=IntVal.intValue(); Object to Primitive integer
float f=FloatVal.floatValue(); Object to Primitive Float
Double d=DoubleVal.doubleValue(); Object to Primitive Double
long l=LongVal.longValue(); Object to Primitive long

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Converting Number to String Using to Stirng() Method
Converting String object to Number Object Using to Static Method ValueOf()
Converting Number String To Primitive Number Using Parsing Methods
Method Calling Conversion Action
Str=Integer.toStiring(i); Primitive integer to String
Str=Float.toFloat(f); Primitive Float to String
Str=Double.toDouble(d); Primitive Double to String
Str=Long.toStiring(l); Primitive Long to String
Method Calling Conversion Action
DoubleVal=Double.valueOf(str); Convert string to Double Object
FloatVal=Float.valueOf(str); Convert string to Float Object
IntVal=Integer.valueOf(str); Convert string to Integer Object
LongVal.Long.valueOf(str); Convert string to Long Object
Method Calling Conversion Action
Int i=integer.parseInt(str); Convert string to primitive integer
float f=Float.parseFlaot(str); Convert string to primitive Float
long l=long.parseLong(str); Convert string to primitive Long
double d=double.parseDouble(str); Convert string to primitive double

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Converting Primitive number 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 Object to Numeric Object

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Converting Number String To Primitive Number
Auto Boxing and Unboxing
The auto boxing and unboxing feature, introduce in J2SE 5.0,
facilitates 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 compiling generates code implicitly
to convert primitive type to the corresponding wrapper classes type
and vice versa for example consider the following statement
Double d_object=98.42;
double d_primitive = d_object.doubleValue();
Usimg the auto boxing and unboxing feature we can rewrite the
above code as:

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Double d_object=98.42;
double d_primitive = d_object;
How the java compile provides restriction to perform the following
conversion.
1. Convert from null type to any primitive type.
2. Convert to null type other than the identify conversion
3. Convert from and class type C to any array type if C is Not
object.
Vector Without using auto boxing and unboxing

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Vector With using auto boxing and unboxing
Nesting of Method
We discussed earlier that a method of class can be called only by
an object of that class (or class itself, in the class of static methods)
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 class.
Program illustrate the nesting of class:
The class nesting define one constructor and two method, namely
largest() and display(). The method display() call the method
largest() to determine the largest of the two numbers and then
displays the result.

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A method can call any number of method. It is also possible for a
called method to call another method. That is, Method 1 may call
Method 2, which in turn may call Method 3.

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