Sudarshan Joshi,BCA 2nd Year
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This document is a project report by Sudarshan Joshi from Dezyne E’cole College focusing on Java programming, specifically on wrapper classes and method nesting. It discusses the conversion of primitive data types to wrapper classes and demonstrates auto boxing and unboxing features, as well as method nesting in Java. The content serves as a theoretical guide for understanding basic Java concepts and includes practical examples.
Sudarshan Joshi,BCA 2nd Year
- 1. INFORMATION TECHNOLOGY Project Report Java Programming Topic Wrapper Class and Nesting Method Submited By Sudarshan Joshi BCA - II year Dezyne E’cole College www.dezyneecol.com
- 2. 1 Project Report On Java Program At Dezyne E’cole College Ajmer Submitted to Dezyne E’cole College Towards The Partial Fulfillment on BCA (Bachelor of Computer Application) By Sudarshan Joshi Dezyne E’cole College 106/10, Civil Lines, Ajmer Tel.-0145-2624679 www.dezyneecole.com 2016-2017
- 3. 2 ACKNOWLEDGMENT I Sudarshan Joshi, Student Of Dezyne E’cole College, An Extremely Granted 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 Supervision As Well As For Providing The Necessary Information And Support Regarding The Completion Of Project. THANK YOU.
- 4. 3 Synopsis This project is a Miner project Made, based on The Theoretical Concept of Java This Project has made our Basic Concept on Java Strong.
- 5. 4 Wrapper Classes:- As pointer out earlier, vectors cannot handle primitive data type 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:- Simply Type Wrapper Class boolean Boolean char Character double Double float Float int Integer long Long The wrapper class have a number of unique methods for handling primitive data type and objects. They are listed in the following table. Converting Primitive number to object number using Constructor method:- Constructor Calling Conversion Active Integer intval =new Integer(i); Primitive integer to Integer Object Float floattval =new Float(f); Primitive float to Float Object Double doubletval =new Double(d); Primitive double to Double Object Long longval =new Long(l); Primitive long to Long Object Converting object number to Primitive number using typevalue () method:- Method Calling Conversion Active Int i=Integer.intValue(); Object to primitive integer float f=Float.floatValue(); Object to primitive Float double d=Double.doubleValue(); Object to primitive Double long l=Long.longValue(); Object to primitive Long
- 6. 5 Converting Number to String using toString () method:- Method Calling Conversion Active str=Integer.toString(i); primitive integer to string str=Float.toString(f); primitive Float to string str=Double.toString(d); primitive Double to string str=Long.toString(l); primitive Long to string Converting String object to Numeric objects using the String Method valueOf ():- Method Calling Conversion Active IntegerVal=Integer.valueOf(str) Converts string to Integer object FloatVal=Float.valueOf(str) Converts string to Float object DoubleVal=Double.valueOf(str) Converts string to Double object LongVal=Long.valueOf(str) Converts string to Long object Converting Numeric String to Primitive Number using Parsing method:- Method Calling Conversion Active Int i=Integer.parseInt(str); Converting String to Primitive integer Long l=Long.parseLong(str); Converting String to Primitive long
- 7. 6 1.Convert Primitive number to object numbers:- Output:-
- 8. 7 2. Convert object numbers to Primitive number:- Output:-
- 9. 8 3.Converting Number to String:- Output:-
- 10. 9 4.Convert String object to Numeric object:- Output:-
- 11. 10 5.Convert Numeric String to Primitive Number:- Output:-
- 12. 11 Auto Boxing and Unboxing:- The auto boxing and unboxing feature, introduced in J2SE 5.0 facilitates the process of handling primitive data type in collections. We can use this feature to convert primitive data type to wrapper class type automatically. The compiler generates a code implicitly to convert primitive type to the corresponding wrapper class type and vice versa. For example, consider the following statement:- Double d=98.42; double dbl=d.doubleVlaue(); Using the auto boxing and unboxing feature, we can rewrite the avoid code as: Double d=98.42; Double dbl =d; How, the java complier provides restrictions 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.
- 13. 12 6.Vector without using auto boxing and unboxing:- Output:-
- 14. 13 7. Vector with using auto boxing and unboxing:- Output:- Method of Nesting:- We discuss earlier that a method of the class can be called by an object of that class (or class itself, in the case of static methods) using the dot operator. How’s, ever there 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 display the result.
- 15. 14 1.Nesting of method:- Output:- 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 call method 2, which is turn may call method 3.
- 16. 15 2.Another example of Nesting of Method :- Output:-
- 17. 16 Thank You