OUR COLLEGE

OUR COLLEGE

ABOUT OUR COLLEGE

G.Pullaih College of Engineering and Technology briefly called as GPCET is one among the best educational institutes founded by Sri Guduri Pullaiah garu,a renowned Educationalist in the Kurnool District of Andra Pradesh state.

VISION:

To flourish as a"Center for excellence" this college offered Technical Education and Reasearch Oppurtunities of very high standards to students instill high levels of discipline and strives to set global standards,making students technologically superior and ethically strong,who inturn shall contribute to the advancement of society and human kind

DESIGN PHILOSOPHY

This logo is very contemporary in design.It is based on the theme of convergence.The different swatches of colours represent the different concentrations,coming together in a beautiful convergence,giving rise to a remarkable scene lifted from nature.Convergence by meaning is,"To come together from different directions."

This logo epitomizes GPCET to be the icon of knowledge,and communicates the institution's pioneering vision of a beautiful convergence of innovation and education in its different concentrations.
Colour in the logo is mainly the synchronisation and convergence representing various concentrations individually and merging together as a knowledge bank.The GPCET. The tag line reinforces the vision-'Pioneering Innovative Education'.

DESCRIPTION OF COLOURS

Brick red----->Stands for Strength
Ink Blue---->Represents Energy
Deep Yellow[denoting sunlight]---->Positive Flow of Energy and Joy of Learning
SpringGreen[denoting Growth]---->Creativity & Intelligence
MoonGreen---->Hope[a Bright Future]
IceBlue---->Vibrance emanating from the confidence of Knowledge

Tuesday, August 18, 2009

JAVA CONCEPTS

1. What is the definition of java?

Java is a high level language which helps us to develop the applications using object oriented methodologies.

2. What is the definition of class?
A class is a blue print for an object and it passes some Instructions to the JVM at runtime to create an object of that type.
OR
A class contains data and the eligible code that acts upon the data and class is a basis for encapsulation.
OR
A class is a template that defines how an object will look and behave when the object is created.
3. What is the definition of object?

An object is a software bundle that holds the data and the code that acts upon the data.

4. What are the features of java?

Architectural and neutral
Robust
Object oriented
Portable
Simple

5. What is the definition of an interface?


An interface is a contractor between service provider and service utilizer.


6. What are the differences between method signature and method prototype?

Method signature is the name of the method followed by the parameters where as method prototype is the overall method type including the return type.


7. What are the similarities between abstract class and interface?

Both can’t be instantiated.
Both can have zero or more number of abstract methods.
We can create references for both of them.
Both can participate in dynamic method dispatch.

8. What are the differences between abstract class and interface?

Abstract class can’t participate in multiple inheritance where as interfaces can participate in multiple inheritance.
Abstract classes can have both concrete methods and abstract methods where as interfaces can have only abstract methods.
Abstract classes can have constructors but interfaces can’t have constructors.
Abstract classes can have instancevariables , class variables and constants where as interfaces can have only static and final variables.
Abstract classes are used for generalization where as interfaces are used for specialization.

9. Can there bf an abstract class with no abstract methods in it?

Yes, an abstract class can have both abstract methods and concrete methods.
The class is javax.servlet.http.httpservlet

10. Can an interface be final?

No, it avoids inheritance and interfaces cannot be final.

11. What is a local , member and a class variable?
Variables declared with in a method are “LOCAL VARIABLES “.
Variables declared with in a class are “MEMBER VARIABLES”.
Variables declared with in a class are “STATIC” or “CLASS VARIABLES”.

12. what modifiers are allowed for methods in an interfaces?
Only public and abstract modifiers are allowed for methods in an interfaces.




13. Can an interface can have an inner class?

Yes
Public interface abc
{
Static int i=0;
Void dd();
Class a1
{
A1()
{
Int j;
System.out.println(“in interia”);
};
Public static void main(String args[])
{
System.out.println(“in interfia”);
}
}
}
14. Can we define private and protected modifiers for variables in interfaces?
No , interfaces have only public , static, final modifiers.
15. What is an externalizable?
Extrenalizable is an interface that extends serializable interface and sends data into streams in compressed format. It has 2 methods
1. writeExternal(object output out)
2. readExternal(objectinput in)
16. What are the different identifiers states of a thread?
The different identifiers of a thread are
R – running or runnable thread
S - suspended thread
CW –thread waiting on a condition variable.
MW – thread waiting on a monitor lock.
MS – thread suspended waiting on a monitor lock.


17. Can we overload main method in java?
Yes, but the main method with string args[] is called when you call the program.
Public class test1
{
Public static void main(String args[])
{
System.out.println(“in main method”);
}
Public static void main(string atgs[],string arg)
{
System.out.println(“in overload method”);
}
}
18. What are the different types of variables in java?
There are 3 types of variables in java. They are
1.local variables
2. static variables
3. member variables.
19. What is meant by type casting?
Type casting is a mechanism of converting the value from one data type to another data type.

20. What is meant by API?
API (Application Program Interface) is a collection of library classes and library packages and library interfaces.
21. What is the role of JVM in java?
JVM (Java Virtual Machine) is a software which converts .class files of one java program into .exe files. It is written in C-language.
22. What is meant by package?
Package is a collection of predefined classes.
23. What is the difference between .class files and .exe files?
.class files are platform independent and system independent where as .exe files are platform dependent and system dependent.
.class files consists of byte code information about the particular java program where as .exe files consists of information about the particular machine.
24. What is meant by byte code?
Byte code is a binary format of a program it is not a machine instructions.
25. What is meant by hash code?
When we are creating an object JVM will give an identity number for that object . That identity number is nothing but hash code.
26. What are the flavours of java?
The flavours of java are
1. J2SE (java 2 standard edition)
2. J2EE (java 2 enterprice edition)
3. J2ME (java 2 micro edition)
27. What is meant by object oriented?
A language is said to be object oriented if every thing is in the form of classes and objects.
28. What are the access specifiers?
Access specifiers are public, private, protected and default.
29. What are the access modifiers?
Access modifiers are abstract, final, native and static.


30. Why the java language is robust?
It provides extensive compile time checkings which was done by compiler at second time of run time checking.
Garbage collection which is responsible for allocating and deallocating the memory for objects that is java programs never suffer from memory leaks.
31. Why java language is simple language?
It does not support pointers and multiple inheritence.
Java draws its roots from C++. C++ is widely used and very popular. It is regarded as complex language with features like multiple inheritance and pointers. Java on the other hand is closure to a pure object oriented language because access to pointers and multiple inheritance are removed.
32. Why java language is architectural- neutral?
Java is both platform independent and system independent .That is it does not depends on the operating system and any systems.
33. What is meant by abstract?
Abstract is the key word which is applicable for classes and methods. We are not allowed to declare a variable as abstract.
34. What is meant by abstract methods?
If a method is declared as abstract it means we don’t know about implementation. Child classes are responsible to provide implementation for parent class abstract methods.
35. What is meant by abstract classes?
If we declare a class as abstract it means we are not allowed to create instance of that class.
If a class contains at least one abstract method we should declare the corresponding class as abstract.
An abstract class not necessary to contain abstract methods always it may contain zero or more number of abstract methods.
Abstract class reference can be created in order to point out its child class objects.


36. Can I have constructors in a abstract class?
Yes , if we are not writing a constructor in a class compiler will give a constructor for us. In a same way abstract class is also one of the normal class in a compiler view. So compiler gives us a default constructor in abstract class but JVM restricts us to create an object.
37. What are the main advantages of interfaces?
Enhancement and security are the main advantages of interfaces.