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Q1: What are the advantages of OOPL?
Ans: Object oriented programming
languages directly represent the real
life objects. The features of OOPL as
inhreitance, polymorphism, encapsulation
makes it powerful.
Q2: What do mean by polymorphisum,
inheritance, encapsulation?
Ans: Polymorhisum: is a feature of OOPl
that at run time depending upon the type
of object the appropriate method is
called.
Inheritance: is a feature of OOPL that
represents the "is a" relationship
between different objects(classes). Say
in real life a manager is a employee. So
in OOPL manger class is inherited from
the employee class.
Encapsulation: is a feature of OOPL that
is used to hide the information.
Q3: What do you mean by static
methods?
Ans: By using the static method there is
no need creating an object of that class
to use that method. We can directly call
that method on that class. For example,
say class A has static function f(),
then we can call f() function as A.f().
There is no need of creating an object
of class A.
Q4: What do you mean by virtual
methods?
Ans: virtual methods are used to use the
polymorhism feature in C++. Say class A
is inherited from class B. If we declare
say fuction f() as virtual in class B
and override the same function in class
A then at runtime appropriate method of
the class will be called depending upon
the type of the object.
Q5: Given two tables Student(SID,
Name, Course) and Level(SID, level)
write the SQL statement to get the name
and SID of the student who are taking
course = 3 and at freshman level.
Ans: SELECT Student.name, Student.SID
FROM Student, Level
WHERE Student.SID = Level.SID
AND Level.Level = "freshman"
AND Student.Course = 3;
Q6: What are the disadvantages of
using threads?
Ans: DeadLock.
Q1: Write the Java code to declare
any constant (say gravitational
constant) and to get its value
Ans: Class ABC
{
static final float
GRAVITATIONAL_CONSTANT = 9.8;
public void getConstant()
{
system.out.println("Gravitational_Constant:
" + GRAVITATIONAL_CONSTANT);
}
}
Q2: What do you mean by multiple
inheritance in C++ ?
Ans: Multiple inheritance is a feature
in C++ by which one class can be of
different types. Say class
teachingAssistant is inherited from two
classes say teacher and Student.
Q3: Can you write Java code for
declaration of multiple inheritance in
Java ?
Ans: Class C extends A implements B
{
} |