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In this article, we’ll discuss about Infosys Interview Questions that are frequently asked by interviewer.

About Infosys

Infosys is one of the India’s leading technology company. Infosys Limited headquarters are in Bengaluru, Karnataka, India. Company trade name as “Infosys Technologies Limited.” This business provides consulting information technology and outsourcing services.

Infosys Technologies Ltd was founded in 1981 and was previously known as Infosys. N. R. Narayana Murthy and a team of six other engineers created Infosys in Pune. The company was founded with a US$250 initial capital commitment.

Infosys assists clients in more than 50 countries in developing and implementing various digital transformation strategies. In addition to assisting clients in improving their overall business performance, Infosys also assists them in becoming a smarter organization. This enables its clients to concentrate on their key business objectives.

Academic Conditions

You must have a grade point average of 60% or better in 10th & 12th.
Graduation: 60% or 6.0 CGPA or equivalent, as determined by the standards of your university.

Company Recruitment and Selection Process

To be chosen for the interview, you must pass three rounds. The first stage consists of an online test that includes logical reasoning and grammar. The second phase is the Technical round, which consists of technical questions, and the third and final round is the HR round, which is the most prevalent round in a company’s recruitment and selection process. The detailed Structure of the three rounds of company recruitment is given below.

First Round- Online Test: In the first round of Infosys recruitment and selection process Grammar and IQ are checked as per the company’s requirements. Some frequently asked analytical questions are given below. Items may change but, grammar and logic will be the same. The difficulty level of this round is moderate. If you have a good IQ and communication skills, then you can easily crack this round.
Second Round- Technical Test: In the second step of the recruitment and selection process Technical questions are asked. You can clear this test if you have good technical knowledge. Be careful while answering questions in the technical round, listen carefully to the interviewer because the technical round is the most difficult round among all the other rounds. The technical round is going to check the technical knowledge you had gained from your previous work experience.
Third Round- HR face-to-face Interview: If you completed the second round then you will be promoted to appear in the third round, which is straight face-to-face HR round. HR is a Human Resource Manager, who is going to talk to you and he is going to ask some questions about the company. I suggest you be cool while answering questions asked in HR round because he is not going to check your technical skill. HR round is not difficult if you have good communication skills. You only have to tell about yourself and the company.

Infosys Technical Interview Questions

1) What is polymorphism?

Polymorphism is a concept by which we can perform a single action in different ways. Polymorphism is derived from two Greek words: poly and morphs. The word “poly” means many and “morphs” means forms. So polymorphism means many forms.

2) Explain the functionality of linked list.

A linked list consists of two parts. Information part and the linked part. In the single linked list, the first node of the list is marked by a unique pointer named as start, and this pointer points to the first element of the list, and the linked part of each node consists of a pointer pointing to the next node, but the last node of the list has null pointer identifying the last node. The linked list can be traversed easily with the help of Start pointer.

3) What is normalization of databases, joins, and keys?

Normalization is also known as the process of organizing data in a DBMS efficiently without any loss of data.

Advantages of the normalization process are as follows

First is eliminating redundant data and ensuring data dependencies make sense. It reduces the amount of space that the database consumes and ensure that data is logically stored.

Join: This clause is used in DBMS to combine rows from two or more tables, based on a related column between them.
Keys: Keys are a crucial part of the relational database model. They are used to identify and establish relationships between tables. They are also used to uniquely determine each record or row of data in a table.
Key: A Key can be a single attribute or a group of attributes acting as a key.

4) What is inheritance?

In, object-oriented programming, inheritance is a mechanism based on classes.

Inheritance refers to inheriting the data members and properties of a parent class to a child class. A class which is derived from another class is often called as a sub-class, and the class from which the child class is derived is known as super-class or parent class.

5) What are the different types of inheritance?

Types of Inheritance:

Single inheritance
Multiple Inheritance
Multi-level Inheritance
Multi-path Inheritance
Hierarchical Inheritance
Hybrid Inheritance

6) Demonstrate the process of inheriting variable of one class to other class?

//Base Class
class A 
{ 
public int a;

}
//Derived Class
class B : A
{
a=15;

}

7) What are the loops statements?

To execute a block of statement several times in a program depending upon the conditional statement loops are used.

The basic structure of a loop is given above in the diagram. For each successful execution of the loop, the conditional statement should be checked. If the conditional statement is true, then the loop will be executed. If the conditional statement is false, then the loop will be terminated.

8) Difference between classes and interface?

The difference between classes and interface are listed below:

The instance of the class can be created by creating its object, whereas interfaces cannot be instantiated as all the methods in the interface are abstract and do not perform any action, There is no need for instantiating an interface.
A class is declared using class keyword whereas an interface is declared using interface keyword.
The members of the class can have access specifier such as public, protected, and private but members of the interface cannot have the access specifier, all the members of the interface is declared as public because the interface is used to derive another class. There will be no use of access specifies inside the members of an interface.
The methods inside the class are defined to perform some actions on the fields declared in the class whereas interface lacks in declaring in fields, the methods in an interface are purely abstract.
A class can implement any number of the interface but can only extend one superclass, whereas interface can extend any number of interfaces but cannot implement any interface.
A class can have a constructor defined inside the class to declare the fields inside the class, whereas interface doesn’t have any constructor defined because there are no fields to be initialized.

9) What is software development life-cycle? Also, explain the waterfall model.

SDLC is a process followed for developing and enhancing software project. It consists of a detailed plan for developing, maintaining a specific software. The life cycle defines a methodology process for improving the quality of software and the overall development process.

In “The Waterfall” model, the whole process of software development is divided into separate phases. In this Waterfall model, typically, the outcome of one phase acts as the input for the next phase sequentially.

10) What are the four basic principles of OOPS?

The four basic principles of Object-Oriented Programming System are listed below:

Abstraction
Inheritance
Encapsulation
Polymorphism.

11) What are the conditional statements?

The conditional statements can alternatively be called a conditional expressions also. Conditional statements are the set of rules which were executed if a particular condition is true. It is often referred to as an if-then statement because if the condition is true, then the statement is executed.

12) What is Database Management System?

A Database Management System is a software system is used for creating and managing databases. DBMS make it possible for the end user to create and maintain databases. DBMS provides an interface between the end user/application and the databases.

13) List different advantages of DBMS.

Improved data sharing.

The list of several advantages of Database Management System:

Improved data security.
Better data integration.
Minimized data inconsistency.
Improved data access.
Improved decision making.
Increased end-user productivity.

14) What do you mean by Object-Relational DBMS?

The object-relational database (ORD) is a database management system (DBMS) that are composed of both an object-oriented database (OODBMS) and a relational database (RDBMS). ORD supports the essential components of an object-oriented database model in its schemas and the query language used, such as inheritance, classes, and objects.

An object-relational database is also known as an object-relational database management systems (ORDBMS).

15) What is database Schema?

It is a set of formulas (sentences) called integrity constraints imposed on a database.

16) What is an IC? What is its importance?

IC refers to integrated circuits sets of electronic circuits on single flat piece semiconductor material, and usually, silicon is used. The integration of a large number of tiny transistors into a small chip results in circuits that are smaller in size and faster than those discrete electronic components. The importance of integrated circuits than the separate electronic components is integrated circuits are smaller in size, faster, low costs than discrete electronic components.

17) Write a program to check whether the input number is a perfect number or not.

// C++ program to check whether the given number is a perfect number or not

#include <iostream>
using namespace std;

int
main ()
{
  int i, num, sum = 0;

  cout <<"\nEnter a number:";
  cin >> num;

  for (i = 1; i < num; i++)
	{
	  if (num % i == 0)
		{
		  sum += i;
		}
	}

  if (sum == num)
	{
	  cout << "\n"<<num << " is a Perfect Number \n" ;
	}
  else
	{
	  cout << "\n"<<num << " is not a Perfect Number\n";
	}

  return 0;
}

18) Tell me something about DSN?

A Data Source Name as the name suggests it is the logical name for Open Database Connectivity to refer to other information that is required to access data. For a connection to an ODBC data source Microsoft SQL Server database.

19) What is the difference between a Clustered-index and a non-clustered-index?

Clustered Index – Only one per table is allowed.
Faster to read than non clustered because the data is physically stored in index order.
Non-Clustered Index – Can be used many times in a table.
Quicker for inserting and updating operations than a clustered index.

20) Difference between C & embedded C.

C Language

C is a type of the computer programming language. C was initially developed by Dennis Ritchie in AT&T Bell Labs between 1969 and 1973. It has a free-format program source code. C is a general-purpose programming language.
C is generally used for desktop computers
C can use the resources of a desktop PC like memory, OS, etc.
Compilers for C (ANSI C) typically generate OS dependent executables.

Embedded C

Embedded C is the set of language extensions for the C Programming language. It was released by the C Standards committee. Through the Embedded C extensions, the C Standards committee hoped to address the commonality issues that exist between C extensions for different embedded systems.
Embedded C is for micro-controller based applications.
Embedded C is used with the limited resources, such as RAM, ROM, I/Os on an embedded processor.
Embedded C requires compilers to create files to be downloaded to the micro-controllers/microprocessors where it needs to run.

21) What is a pointer in C? What is its use?

The pointer is a particular variable which holds the address of another variable of the same type. Pointers can be of any data type and structure are allowed in C programming language. Pointer variable stores the address of another variable of the same data type as the value of the pointer variable.

Following are the uses of pointers:

To point a variable in the memory.
Pointers are used to traverse the linked list.
To point out a structure.

22) Different between a session and a socket?

The Socket is the Combination of Ip address, and Port Number and the session is a Logical Connectivity between the source and destination.

23) What is a null pointer?

The null pointer is the pointer with no reference to any location of the memory.

A null pointer contains zero as its value which means pointer is empty and not pointing to anywhere in the memory. Null pointers can be used further in the program to initialize the address of the memory location with the same data type of the pointer.

Note: Pointers can only point to the variable having the same datatype. If the data type of pointer and datatype of pointing variable is different, then the pointer will not work.

24) What is a Real-Time OS?

A real-time operating system is an operating system which acts as an interface between hardware and user. This system guarantees a specific capability within a specified time. For example, an operating system is designed to ensure that a specific object was available for a robot on an assembly line.

25) Difference between TCP and UDP

TCP	UDP
Connection-orientated protocol	Connectionless protocol
Segment sequencing.	No sequencing.
Acknowledge sequencing	No windowing and retransmission.
Reliable transmission protocol.	Unreliable transmission protocol.

26) Write a c program to swap two numbers without using a temporary variable.

void
swap (int &i, int &j)
{
  i = i + j;
  j = i - j;
  i = i - j;
}

27) Which functions are used for memory allocation in C/C++

The Function calloc() allocates a memory area, and the length will be the product of its parameters(it has two parameters). It fills the memory with ZERO’s and returns a pointer to the first byte of the memory. If it fails to locate enough space, Then it returns a NULL pointer.

The function malloc() allocates a memory area, and length will be the value entered as a parameter. (it has one parameter). It does not initialize memory area free() used to free the allocated memory(allocated through calloc and malloc), in other words, this used release the allocated memory new also used to allocate memory on the heap and initialize the memory using the constructor delete also used release memory allocated by new operator

28) Write output of the program?

int i=10;
printf("%d%d%d",i,++i,i++);     //10 12 12

29) What is a virtual function and what is the pure virtual function?

Virtual function:- In order to achieve polymorphism, function in base class is declared as virtual, By declare virtual we make the base class pointer to execute the function of any derived class depends on the content of pointer (any derived class address).

Pure Virtual Function:- This is a function used in base class, and its definition has to be provided in a derived class, In other pure virtual function has no definition in the base is defined as:

virtual void fun()=0;

That means this function not going to do anything, In case of the pure virtual function derived function has to implement the pure virtual function or redeclare it as the pure virtual function

30) What are WPF-WCF?

WPF/WCF application, need in .NET 3.0 Framework. This application will cover the following concepts:

WCF(Windows Communication Foundation)
The new service orientated attributes
The use of interfaces
The use of callbacks
Asynchronous delegates
Creating the proxy
WPF( Windows Presentation Foundation )
Styles
Templates
Animations
Databinding
Multithreading a WPF application

31) Difference between the EXE and the DLL file extension?

The term EXE is a short-term of the word executable as it identifies the file as a program. Whereas, DLL stands for Dynamic Link Library, which commonly contains functions and procedures that can be used by other programs.

32) Scenarios in which the web application should be used and scenarios in which desktop application should be used?

Scenarios in which web application used are listed below:

Cost effective development
Accessible anywhere
Easily customizable

Scenarios in which desktop application should be used are listed below:

Desktop application usually has more control.

Safe for computationally expensive software that needs to communicate directly with the OS.

The desktop application is often offline and does not need an Internet connection to function compared to a web application.

33) What is an array?

An array is a group of elements used to store a group of related data of the same data type.

The array uses index number to identify each element in an array.

33) Compare between Inner Join Vs Outer Join?

Inner Join	Outer Join
Only matching records or values from both the database tables are taken where there is a common ID.	All the records from the database tables are taken, and a common ID is not required at all.
All rows will have any value because these are taken from the table with the same entries.	In outer join, some entries may return a null value.
There are no alternatives or variants of inner join.	Outer join can be left, right, or full join.
The optimizer can be used as it gives many valuable options.	Optimizer use in the outer join is very limited because the joins take all the entries, and its usage is not practicable.
The results provided by the inner join have the least entries and will be able to update the user requirements.	As you know, outer join has different options such as left, right, and full join, so its usage must be monitored and checked thoroughly.
You can observe the lack of performance because SQL inner join is slower.	Outer joins especially left outer joins, are faster and better performance in most cases.
The satisfaction of the inner join condition is mandatory.	There are no conditions that we have to meet in the outer join query necessarily.
There is no output of those entries having no matching with the entries of another table.	If entries of one table do not have any matching with another table, then you will get null values.
It is a straightforward process in which the matching values should not be considered for left or right tables.	In outer join, when the entries match, it will check either condition is given for left or right tables, and entry is considered accordingly except full outer join.
If a related data entry is needed as per the customer requirement or database design, then the inner join is recommended.	If a related data entry is not required as per the customer requirement or database design, then the outer join is more suitable.

35) What are the SQL tables?

A table is a set of related data in a structured format in the database. A table is consists of rows and columns.

36) What is the difference between array and pointer?

An array is the group of similar elements having the same data type, whereas the pointer is a variable pointing to some data type in the memory. Arrays can only contain the elements of similar data type whereas pointer variable is used to point to any data type variable.

37) How abstraction and encapsulation complementary?

Abstraction and encapsulation are complementary because in object-oriented programming classes can only be abstracted if it is encapsulated. The abstraction focuses on the observable behavior of an object, whereas encapsulation focuses on the implementation that gives rise to this behavior.

38) How is modularity present in C++?

Modularity is the concept explained in oops concept, and it was introduced with class and objects in c++. Functions, classes, structures implements modularity in C++.

39) Define the structural difference between the b-tree index and bitmap?

Btree

This tree structure was developed by Bayer and McCreight in 1972.This tree structure is a height-balanced m-way search tree. A B-tree of the order m can be defined as an m-way search tree.

It is made up of branch nodes and leaf nodes.

Bitmap

It consists merely of bits for every single distinct value. It uses a string of bits to locate rows in a table quickly. Used to index low cardinality columns.

40) What do you mean by platform independence?

Platform independence is a term that describes a technology (usually a programming language or a FrameWork) that you can use to implement things on one machine and use them on another machine without (or with minimal) changes.

Hope this article on Infosys Interview Questions is helpful to you. Feel free to comment for suggestions to improve and ask a question!

Infosys Interview Questions interview questions

Infosys Interview Questions