50+ Infosys System Engineer Hardware Interview Questions and Answers

Counting letter-pairs with same no. of letters left between them in the word SERVANT.

• Identify the letter-pairs in the word SERVANT.

• Count the number of letters between each pair.

• Compare the count with the position of the pair in the word.

• If they match, increment the count of such pairs.

• Answer the total count of such pairs.

Explains difference between string object, string literal and string buffer. Also, sorts array and finds pair of numbers.

• String object is an instance of a class, string literal is a sequence of characters enclosed in double quotes, and string buffer is a mutable sequence of characters.

• To sort an array of strings, use Arrays.sort() method.

• To find a pair of numbers in an array that add up to a target value, use a nested loop to compare each element with every other element.

• Exam...read more

Programming is essential for automating tasks, solving complex problems, and creating innovative technologies.

• Programming is needed to automate repetitive tasks and increase efficiency.

• It is essential for developing software applications, websites, and mobile apps.

• Programming allows for the creation of innovative technologies like artificial intelligence and virtual reality.

• Object-oriented programming (OOP) is a programming paradigm based on the concept of objects, which can ...read more

Data hiding is hiding the implementation details while abstraction is hiding the complexity of the system.

• Data hiding is a technique to hide the implementation details of a class from the outside world.

• Abstraction is a technique to hide the complexity of the system by providing a simplified interface.

• Data hiding is achieved through access modifiers like private, protected, and public.

• Abstraction is achieved through abstract classes and interfaces.

• Data hiding is used to preven...read more

ACID properties are a set of properties that ensure reliability and consistency of data in a database.

• ACID stands for Atomicity, Consistency, Isolation, and Durability.

• Atomicity ensures that a transaction is treated as a single, indivisible unit of work.

• Consistency ensures that the database remains in a valid state before and after a transaction.

• Isolation ensures that concurrent transactions do not interfere with each other.

• Durability ensures that once a transaction is commit...read more

Explanation of Collection API, ArrayList internal implementation and syntax for HashMap

• Collection API is a set of interfaces and classes that provide a framework for handling groups of objects

• ArrayList is a resizable array implementation of List interface in Collection API

• ArrayList internally uses an array to store the elements and dynamically increases its size as required

• Syntax for HashMap: HashMap map = new HashMap();

Yes, I am familiar with ticketing tools.

• I have experience using JIRA for issue tracking and project management.

• I have also used ServiceNow for IT service management.

• Other ticketing tools I am familiar with include Zendesk and Freshdesk.

• I understand the importance of using ticketing tools to efficiently manage and track issues.

• I am comfortable using ticketing tools to communicate with team members and stakeholders.

A signal is a physical quantity that varies with time, conveying information. A sine wave is a periodic signal.

• A signal can be electrical, acoustic, or optical.

• Signals can be analog or digital.

• Examples of signals include sound waves, radio waves, and voltage signals.

• A sine wave is a smooth, repetitive oscillation that can be described mathematically.

• It is characterized by its amplitude, frequency, and phase.

DELETE is a SQL command used to remove rows from a table.

• DELETE is used with the WHERE clause to specify which rows to remove

• It can also be used with JOIN to delete rows from multiple tables

• The deleted rows can be recovered using the ROLLBACK command

Learning Python as a newbie

• Start with basic syntax and data types

• Practice coding exercises and challenges

• Read documentation and watch tutorials

• Join online communities and forums for support

• Work on personal projects to apply knowledge

CSS can be included in HTML in three main ways: inline, internal, and external.

• Inline CSS - using the style attribute within an HTML element

• Internal CSS - using the <style> tag within the <head> section of the HTML document

• External CSS - linking an external CSS file to the HTML document using the <link> tag

OOPs concepts are the fundamental principles of Object-Oriented Programming that help in designing and implementing software systems.

• Encapsulation: bundling of data and methods that operate on that data

• Inheritance: creating new classes from existing ones

• Polymorphism: ability of objects to take on multiple forms

• Abstraction: hiding implementation details and showing only functionality

• Examples: Java, C++, Python, Ruby

Place by value passes a copy of the value, while place by reference passes a reference to the original value.

• Place by value creates a new copy of the value, while place by reference uses the original value.

• Place by value is used for simple data types like integers and floats, while place by reference is used for complex data types like arrays and objects.

• An example of place by value is passing an integer to a function, while an example of place by reference is passing an arra...read more

Computer Networking: A Top-Down Approach by James Kurose and Keith Ross

• Provides a comprehensive overview of computer networking concepts and protocols

• Covers both theoretical foundations and practical applications

• Includes real-world examples and case studies for better understanding

Use SQL query with LIMIT clause to display top 5 rows from a table.

• Use SELECT statement to retrieve data from the table

• Add LIMIT 5 at the end of the query to display only the top 5 rows

OOPs principles are encapsulation, inheritance, and polymorphism.

• Encapsulation is the process of hiding implementation details from the user.

• Inheritance allows a class to inherit properties and methods from another class.

• Polymorphism allows objects to take on multiple forms or behaviors.

• Abstraction is the process of hiding complex implementation details from the user.

• Objects are instances of classes that contain data and behavior.

• Classes are templates for creating objects wit...read more

Languages that support OOPS concept include Java, C++, Python, C#, and Ruby.

• Java

• C++

• Python

• C#

• Ruby

Different types of CSS styling include inline, internal, external, and imported stylesheets.

• Inline CSS is applied directly to an HTML element using the style attribute.

• Internal CSS is defined within the head section of an HTML document using the style tag.

• External CSS is stored in a separate file and linked to the HTML document using the link tag.

• Imported stylesheets allow for modular CSS by importing one stylesheet into another using the @import rule.

OOPS stands for Object-Oriented Programming System. It is a programming paradigm based on the concept of objects.

• OOPS is based on four main concepts: encapsulation, inheritance, polymorphism, and abstraction.

• Encapsulation is the process of hiding the implementation details of an object from the outside world.

• Inheritance allows a class to inherit properties and methods from another class.

• Polymorphism allows objects of different classes to be treated as if they were of the same...read more

Python is a versatile programming language used in various real-world applications such as web development, data analysis, artificial intelligence, and automation.

• Web development: Django and Flask are popular Python frameworks for building websites and web applications.

• Data analysis: Python is widely used in data science for tasks like data cleaning, visualization, and machine learning.

• Artificial intelligence: Python libraries like TensorFlow and PyTorch are used for developi...read more

Scrum is an agile framework for managing and completing complex projects.

• Scrum involves a team working together to complete a project in short iterations called sprints.

• The team has daily stand-up meetings to discuss progress and plan for the day.

• Scrum emphasizes flexibility and adaptability to changing requirements.

• The product owner prioritizes the backlog of work and the team works to complete the highest priority items first.

• Scrum includes roles such as the Scrum Master, P...read more

Hash maps and hash tables are data structures that store key-value pairs and use a hash function to map keys to values for efficient retrieval.

• Hash maps and hash tables are used to implement associative arrays, dictionaries, and sets.

• They use a hash function to compute an index into an array of buckets or slots, where the value is stored.

• Collision resolution techniques like chaining or open addressing are used to handle situations where multiple keys map to the same index.

• Exa...read more

A program to calculate factorial of a number.

• Take input from user

• Use a loop to multiply the number with all the numbers less than it

• Print the result

A prime number is a number greater than 1 that can only be divided by 1 and itself.

• A prime number has exactly two distinct positive divisors: 1 and itself.

• Examples of prime numbers include 2, 3, 5, 7, 11, 13, 17, etc.

• To determine if a number is prime, check if it is divisible by any number other than 1 and itself.

Different network topologies include bus, star, ring, mesh, and hybrid.

• Bus Topology: All devices are connected to a central cable.

• Star Topology: All devices are connected to a central hub.

• Ring Topology: Each device is connected to exactly two other devices, forming a ring.

• Mesh Topology: Each device is connected to every other device in the network.

• Hybrid Topology: Combination of two or more different topologies.

Java and C++ are object-oriented languages while C is a procedural language.

• Java and C++ have built-in support for object-oriented programming concepts like inheritance, polymorphism, and encapsulation.

• C++ allows for low-level memory manipulation and has better performance than Java.

• C is a procedural language and lacks the object-oriented features of Java and C++.

• C is commonly used for system programming and embedded systems.

• Java is platform-independent while C++ and C are pl...read more

Explanation of various sorting algorithms and their time complexities

• Bubble Sort - O(n^2)

• Selection Sort - O(n^2)

• Insertion Sort - O(n^2)

• Merge Sort - O(n log n)

• Quick Sort - O(n log n)

• Heap Sort - O(n log n)

• Radix Sort - O(nk)

An array in C is a collection of similar data types stored in contiguous memory locations.

• Arrays are declared using square brackets []

• Elements in an array can be accessed using their index number

• Arrays can be initialized during declaration

• Arrays can be passed as arguments to functions

• Example: int arr[5] = {1, 2, 3, 4, 5};

• Example: printf("%d", arr[2]); // Output: 3

A pointer in C is a variable that stores the memory address of another variable.

• Pointers are used to manipulate data directly in memory.

• They can be used to pass data between functions efficiently.

• Pointers can be used to dynamically allocate memory.

• Example: int *ptr; ptr = # *ptr = 10; // num now equals 10

SDLC stands for Software Development Life Cycle, a process used to design, develop, and maintain software.

• SDLC is a structured approach to software development.

• It involves several stages such as planning, analysis, design, implementation, testing, and maintenance.

• Each stage has its own set of activities and deliverables.

• SDLC ensures that software is developed efficiently, on time, and within budget.

• Examples of SDLC models include Waterfall, Agile, and DevOps.

An airplane flies due to the principles of aerodynamics and the use of engines to generate thrust.

• Airplanes generate lift through the shape of their wings and the Bernoulli's principle.

• Thrust is generated by the engines, which propel the airplane forward.

• The airplane's weight is counteracted by the lift generated by the wings.

• Control surfaces such as ailerons, elevators, and rudder are used to control the airplane's movement.

• Pilots use instruments and controls to monitor and ...read more

Stack, Queue, and Binary Search are common data structures used in computer science.

• Stack: Last In First Out (LIFO) data structure. Example: Undo/Redo feature in a text editor.

• Queue: First In First Out (FIFO) data structure. Example: Print queue in a printer.

• Binary Search: Efficient search algorithm for sorted arrays. Example: Searching for a word in a dictionary.

Object-oriented programming concepts that focus on data encapsulation, inheritance, polymorphism, and abstraction.

• Encapsulation: Bundling data and methods that operate on the data into a single unit (object)

• Inheritance: Ability of a class to inherit properties and behavior from another class

• Polymorphism: Ability to present the same interface for different data types

• Abstraction: Hiding the complex implementation details and showing only the necessary features

An array is a collection of elements of the same data type, stored in contiguous memory locations.

• Arrays can be one-dimensional or multi-dimensional

• Elements in an array can be accessed using their index

• Arrays can be initialized with values at the time of declaration

• Examples: int[] numbers = {1, 2, 3}; char[] letters = {'a', 'b', 'c'};

• Arrays in programming languages like C/C++ are pointers to the first element of the array

Abstraction in Java is the concept of hiding the implementation details and showing only the necessary features of an object.

• Abstraction allows you to define the structure of an object without specifying the implementation details.

• It helps in reducing complexity by hiding unnecessary details and only showing the essential parts.

• Abstract classes and interfaces are used to achieve abstraction in Java.

• Example: Abstract class 'Shape' with abstract method 'draw' can be extended by...read more

Pointers in C++ are variables that store memory addresses of other variables.

• Pointers are used to access and manipulate memory directly.

• They are denoted by an asterisk (*) before the variable name.

• Example: int *ptr; // declares a pointer to an integer variable

• Example: ptr = # // assigns the address of 'num' to the pointer

PSVM stands for Parallel Support Vector Machine and SYSO stands for System Output.

• PSVM is a machine learning algorithm used for classification tasks.

• SYSO refers to the output generated by a system or program.

• PSVM can be implemented using libraries like LIBSVM.

• SYSO can include text, images, or numerical data.

HTML tags are used to define the structure and content of a web page.

• HTML tags are enclosed in angle brackets, such as <tag>.

• They are used to format text, insert images, create links, etc.

• Examples include <p> for paragraphs, <img> for images, <a> for links.

SDLC stands for Software Development Life Cycle. It is a process used to design, develop, and maintain software systems.

• SDLC is a structured approach to software development.

• It consists of several phases including requirements gathering, design, coding, testing, deployment, and maintenance.

• Each phase has specific activities and deliverables.

• SDLC helps ensure that software is developed efficiently, meets user requirements, and is of high quality.

• Examples of SDLC models include...read more

OOPs stands for Object-Oriented Programming which is a programming paradigm based on the concept of objects.

• OOPs focuses on creating objects that have properties and methods

• It allows for encapsulation, inheritance, and polymorphism

• Examples of OOPs languages include Java, C++, and Python

Abstraction is the process of hiding complex details and showing only the essential features of an object or system.

• Abstraction allows us to focus on what an object does instead of how it does it

• It helps in reducing complexity and improving efficiency

• Examples include using a car without knowing the internal combustion engine details, or using a smartphone without understanding the hardware components

Classes and objects in C++ are used to create user-defined data types with their own properties and behaviors.

• Classes are used to define the blueprint for objects, containing data members and member functions.

• Objects are instances of classes, created using the 'new' keyword.

• Encapsulation, inheritance, and polymorphism are key concepts in object-oriented programming with C++.

Quick sort is a divide-and-conquer algorithm that sorts an array by selecting a pivot element and partitioning the array around the pivot.

• Select a pivot element from the array

• Partition the array into two sub-arrays: elements less than the pivot and elements greater than the pivot

• Recursively apply the same process to the sub-arrays

• Combine the sorted sub-arrays to get the final sorted array

Merge sort is a divide and conquer algorithm that divides the input array into two halves, sorts them separately, and then merges them.

• Divide the array into two halves

• Recursively sort each half

• Merge the sorted halves back together

Scenario Outline is a feature in Cucumber that allows for running the same test scenario with different inputs

• Scenario Outline is used in Cucumber to create a template for a scenario that can be run multiple times with different inputs

• It uses placeholders (e.g. ) in the scenario steps that are replaced with actual values from a data table

• Each row in the data table represents a set of inputs that will be used to run the scenario

• Scenario Outline is useful for testing the same f...read more

Binary search is a divide and conquer algorithm that efficiently finds the target value within a sorted array.

• Start by defining the low and high indices of the array.

• Calculate the mid index as (low + high) / 2.

• Compare the target value with the value at the mid index and adjust the low and high indices accordingly.

• Repeat the process until the target value is found or the low index surpasses the high index.

OOPs concepts include inheritance, polymorphism, encapsulation, and abstraction.

• Inheritance: Allows a class to inherit properties and behavior from another class.

• Polymorphism: Ability for objects of different classes to respond to the same method.

• Encapsulation: Bundling data and methods that operate on the data into a single unit.

• Abstraction: Hiding the complex implementation details and showing only the necessary features.

Dijkstra algorithm is a graph search algorithm that finds the shortest path between nodes in a graph.

• Dijkstra algorithm starts at a selected node and explores the neighboring nodes to find the shortest path.

• It uses a priority queue to keep track of the nodes to be explored next based on their distances from the starting node.

• The algorithm continues until all nodes have been visited and the shortest path to each node has been determined.

Event loop in JavaScript is a mechanism that allows for asynchronous operations to be executed in a non-blocking way.

• Event loop is responsible for handling asynchronous operations in JavaScript.

• It allows for tasks to be queued and executed in a non-blocking manner.

• Event loop continuously checks the call stack and the task queue, moving tasks from the queue to the stack when the stack is empty.

• Example: setTimeout function in JavaScript uses the event loop to execute a function...read more