About this previous year paper
SECTION–A (2 Marks Each)
a) Link vs Association
Association shows a relationship between two classes (e.g., Teacher–Student).
Link is an actual instance of an association (e.g., Mr. Sharma teaches Rahul).
b) Abstract Class
An abstract class is a class that contains at least one pure virtual function.
Yes, an abstract class can be inherited, but the derived class must implement all abstract methods.
c) State Diagram of Electric Bulb
States:
OFF → Switch ON → ON
ON → Switch OFF → OFF
d) Protected Visibility Specifier
Used when class members should be accessible inside the class and its derived classes, but not outside.
e) Inline Function
A function is made inline when it is small and frequently used.
It reduces function call overhead and improves performance.
f) Destructor
A destructor is a special function used to free memory and resources when an object is destroyed.
g) Scope Resolution Operator (::)
Used to access: Global variables
Class methods outside the class Static class members
h) Candidate Key
A candidate key is a minimal attribute that can uniquely identify a record in a table.
i) Friend Function
A friend function can access private and protected members of a class without being its member.
j) Information Hiding
It means restricting direct access to object data and exposing only necessary details.
SECTION–B (Attempt Any Three – 10 Marks Each)
a) Constructor & Constructor Overloading
A constructor is a special function that initializes objects.
Characteristics
Same name as class No return type Automatically called
Constructor Overloading Example
class Demo { public: Demo() { cout << "Default Constructor"; } Demo(int x) { cout << "Parameterized Constructor"; } };
b) Inline Function
Inline functions reduce execution time by avoiding function calls.
inline int square(int x) { return x * x; }
c) Object Oriented Programming (OOP)
OOP organizes programs using objects and classes.
Advantages
Code reusability Security Easy maintenance
Prime Number Program Using Class
class Integer { public: void printPrime(int n) { for(int i=2;i<n;i++) { bool prime=true; for(int j=2;j<i;j++) { if(i%j==0) prime=false; } if(prime) cout<<i<<" "; } } };
d) Basic Concepts of OOP
Class Object Encapsulation Inheritance
Polymorphism Abstraction
e) Inheritance
Inheritance allows one class to acquire properties of another.
Types
Single Multiple
Multilevel Hierarchical
Hybrid
Multiple Inheritance Example
class A { }; class B { }; class C : public A, public B { };
SECTION–C (10 Marks)
Polymorphism
Ability of one function to behave differently.
Compile Time
Function overloading Operator overloading
Run Time
Function overriding Virtual functions
Operator Overloading Example
class Test { public: int x; Test operator+(Test t) { Test temp; temp.x = x + t.x; return temp; } };
SECTION–D
Farmer–Goat–Lion–Grass Problem
Safe Steps
Take goat across Return alone
Take grass across Bring goat back
Take lion across Return alone
Take goat across
(Event trace diagram explanation can be written step-wise in exam)
Multiplicity & Quantification
Multiplicity defines number of objects in relation (1..1, 1..*, etc.)
Example: One teacher teaches many students
SECTION–E
UML
UML is a visual modeling language used to design systems.
Building Blocks
Things Relationships Diagrams
Types of Things
Structural Behavioral
Grouping Annotational
Virtual Base Class Used to avoid ambiguity in multiple inheritance.
class A { }; class B : virtual public A { }; class C : virtual public A { }; class D : public B, public C { };
SECTION–F
Type Conversion
Implicit: Done automatically by compiler
Explicit: Done manually using casting
Generalization, Aggregation & Association
Generalization: IS-A relationship
Aggregation: HAS-A (weak)
Association: Logical connection
SECTION–G
Friend Function Example
class Test { int x; public: friend void show(Test); }; void show(Test t) { cout << t.x; }