Oop Interview

Front 1

What is OOP?

Back 1

Programming language model organized around objects rather than "actions" and data rather than logic.

Front 2

Basic concepts of OOP?

Back 2

-Encapsulation

-Inheritance

-Polymorphism

-Abstraction

Front 3

What is a class?

Back 3

A class is simply a representation of a type of object. It is the blueprint that describes the details of an object

Front 4

What is a object?

Back 4

An instance of a class. It has its own state, behaviour and identity

Front 5

What is Encapsulation?

Back 5

Encapsulation is a mechanism of wrapping the data and methods together as a single unit.

Hides the properties and methods which protect the code from accidental corruption.

Front 6

What is Abstraction?

Back 6

Process of hiding the implementation details from the user, only the functionality will be provided to the user.

Front 7

What is polymorphism?

Back 7

Polymorphism is the programming language's ability to process objects differently depending on their data type or class. More specifically, it is the ability to redefine methods for derived classes.

Front 8

What is inheritance?

Back 8

Inheritance is a concept where one class shares the structure and behavior defined in another class.

Front 9

Define a constructor?

Back 9

A method used to initialize the state of an object, and it gets invoked at the time of object creation.

-Constructor name should be same as class name

-Constructor must have no return type

Front 10

What is an in-line function?

Back 10

Technique used by the compilers and instructs to insert complete body of function wherever that function is used in the program source code.

Front 11

What is a friend function?

Back 11

Friend function is a friend of a class that is allowed to access public, private or protected data in that same class. If the function is defined outside the class, the class cannot access such information.

Front 12

What is function overloading?

Back 12

Same as a normal function but the ability to perform different tasks. Allows creation of several methods with the same name which differ from each other by type of input and output of the function.

Front 13

What is operator overloading?

Back 13

A function where different operators are applied and depends on the arguments.

Front 14

What is a abstract class?

Back 14

A class which can't be instantiated. Only for inheritance. Can only contain abstract methods.

Front 15

What is a ternary operator?

Back 15

Operator which takes three arguments.

Front 16

What is a singleton pattern?

Back 16

Singleton pattern is a design pattern that restricts the instantiation of a class to one object.

Front 17

When is it used?

Back 17

This is useful when exactly one object is needed to coordinate actions across the system

Front 18

What is a factory method?

Back 18

A interface for creating an instance of a class, with its subclasses deciding which class to instantiate

Front 19

Difference between overloading and overriding?

Back 19

Overloading is static binding (compile time) whereas overriding is dynamic binding (runtime).

Overloading is nothing but the same method with different arguments, and it may or may not return the same value in the same class itself

Overriding is the same method names with same arguments and return types associates with the class and its child class

Front 20

Prime numbers algorithm

Back 20

if n <= 1
return false

if n >= 3

return true

i = 1

While i*i <= n

if n%i == 0

return false

i += 1

return true

Front 21

What is an interface?

Back 21

An interface is a programming structure/syntax that allows the computer to enforce certain properties on an object (class