Fundamental Questions Of Programming Asked In An Interview

What are the concepts of Object Oriented programming?

• Class
• Object
• Inheritance
• Polymorphism
• Abstraction
• Encapsulation
• Access modifiers

Describe the types of join in SQL in detail?

• Join or Inner Join
• Outer join
• Left Join
• Right Join
• Full Join
• Cross Join
• Self-Join

What is class in Object Oriented Programming Language?

A class in object oriented programming defines a category or behaviors of objects and an instance of respective category is the object of that class.A class binds up the data member and member function into single unit.

What is Abstract class? Why we use abstract class?

An abstract class declares common attributes and behaviors of the various classes in a class hierarchy. An abstract class typically contains one or more abstract methods that subclasses must override if the subclasses are to be concrete. The instance variables and concrete methods of an abstract class are subject to the normal rules of inheritance.

Why we use indexes in SQL?

Indexes are created to speed up the operations or to quickly retrieve the data.

What is the use of stored procedure and triggers?

Stored procedure is used to store multiple queries in a single process that reduces the calls from database.

What is the concept of Array?

Arrays are used to store the collection of similar type of data types so that we can work with multiple values with a single loop.

What are different types of loops?

There are 3 type of loops -

• While loop
• Do-While loop
• For loop

What are Data Control Language queries?

There are two types of DCL queries

• Grant
• Revoke

What is the role of constructor?

Constructors are created for efficient memory management which is not possible with functions. Every time we don’t need to initialize a constructor because compiler has its own constructor that is default constructor.

When we want some task to be executed while object of the class is created for that we can create a constructor. Constructor is a special type of function the name of the constructor will always be same as the class.

How do you define a function?

A function is a block of code which performs some specific task. When we want to execute same process multiple times that time we can call a function as many times as we want instead of writing the same block of code repeatedly.

What is HTML and CSS?

HTML stands for Hypertext markup language. HTML is mainly used to manage the text content of the page with the help of some predefined selectors.

CSS stands for cascading style sheets. CSS is used to provide designing effects to the web pages with different variations.

What is Responsive Bootstrap?

Bootstrap is a framework which is the combination of HTML, CSS and javaScript. With the help of bootstrap we can create an website which can behave as per the size of the screen.

What is XHTML?

XHTML stands for Extensible hypertext markup language. It means HTML as XML.XHTML is supported by all major browsers

Difference between Abstract and Interface?

We cannot define the behavior of the functions inside an interface whereas in an abstract class we can define the body of the functions.

What is polymorphism?

Poly means more than one. Such functions who can behave like multiple aspects are comes under polymorphism. To perform polymorphism we have techniques -

• Function Overloading
• Function overriding

Overloading - Defining two or more function with the same name and different signature is overloading.

Overriding - Defining two or more function with the same name and same signature overriding.

What is SQL?

SQL is a language to interact with the database or to perform operation in database with the help of multiple commands. All the commands of SQL are categorized in following categories–

• DDL
• DML
• DQL
• TCL

What is the Difference between Candidate key and Composite key?

A candidate key can be a single key or group of keys which resembles a primary key. A composite key is a key of two or more attributesthat uniquely identifies the row.

What is an Unique Key?

Unique key is column that uniquely identifies a row. Unique key can be multiple in a table. Unique can have null values.

What is foreign key and primary key?

A foreign key is a key used to link two tables together which matches a column of primary key