20+ Haresh Electricals Interview Questions and Answers

Polymorphism is the ability of an object to take on many forms.

• It allows objects of different classes to be treated as if they were objects of the same class.

• It is achieved through method overriding and method overloading.

• Example: A shape class can have multiple subclasses like circle, square, triangle, etc. All these subclasses can have a draw() method, but each subclass will implement it differently.

• Another example is the + operator in Python. It can be used to add two inte...read more

Data encapsulation is the process of hiding implementation details and exposing only necessary information.

• It is a fundamental concept in object-oriented programming.

• It helps in achieving data security and prevents unauthorized access.

• It allows for easy modification of implementation details without affecting the rest of the code.

• Examples include private variables and methods in a class.

• It is achieved through the use of access modifiers such as public, private, and protected.

Program to find substring in a string

• Use a loop to iterate through the main string

• Check if the substring matches the characters in the main string

• Return the index where the substring starts, or -1 if not found

My strengths include problem-solving skills, adaptability, and strong communication abilities.

• Strong problem-solving skills - I enjoy tackling complex issues and finding creative solutions.

• Adaptability - I am able to quickly learn new technologies and adapt to changing environments.

• Strong communication abilities - I can effectively communicate with team members and stakeholders to ensure project success.

Code to find words in brackets and add numbers to each unique word

• Iterate through the array of strings

• Use regular expressions to find words in brackets

• Create a dictionary to store unique words and their counts

Program to find the Least Common Multiple (LCM) of two numbers

• Create a function that takes two integers as input

• Find the Greatest Common Divisor (GCD) of the two numbers using Euclidean algorithm

• Multiply the two numbers and divide by their GCD to get LCM

• Example: For numbers 12 and 18, LCM = (12 * 18) / GCD(12, 18)

A constructor is a special type of method that is used to initialize objects in a class.

• Constructors have the same name as the class they belong to.

• They do not have a return type.

• They are called automatically when an object is created.

• Constructors can have parameters to initialize the object with specific values.

Answering SQL questions on finding 2nd top salary and writing inner join query.

• To find 2nd top salary, use the LIMIT keyword with OFFSET 1

• For inner join, use the JOIN keyword with ON clause to specify the join condition

• Example: SELECT * FROM table1 INNER JOIN table2 ON table1.id = table2.id

• Example: SELECT salary FROM employees ORDER BY salary DESC LIMIT 1 OFFSET 1

I would communicate with the stakeholders to understand the reasons behind the deadline and propose a realistic timeline.

• Understand the reasons behind the deadline

• Communicate with stakeholders to propose a realistic timeline

• Prioritize tasks and focus on the most critical ones

• Identify potential risks and plan accordingly

• Be transparent about the progress and any challenges faced

Weigh 3 coins against 3 coins, then weigh the remaining 4 coins against each other to find the lightest one.

• Divide the 10 coins into 3 groups of 3, 3, and 4 coins.

• Weigh the first two groups of 3 coins against each other.

• If they balance, the lightest coin is in the group of 4 coins. Weigh two of them against each other to find the lightest one.

• If they don't balance, the lightest coin is in the group that weighed less. Weigh two of those coins against each other to find the lig...read more

The project follows a microservices architecture with a combination of RESTful APIs and message queues.

• The project is divided into multiple small services that communicate with each other through APIs and message queues.

• Each service is responsible for a specific functionality and can be deployed independently.

• The APIs are designed to be stateless and follow RESTful principles.

• The message queues are used for asynchronous communication between services.

• The project uses containe...read more

Reverse a string by iterating through each character and appending to a new string.

• Create a new empty string to store the reversed string

• Iterate through each character of the original string from end to start

• Append each character to the new string

• Return the reversed string

Two trains are approaching each other from different directions. By calculating the relative speed at which they are approaching each other, we can determine the speed of each train.

• Calculate the relative speed at which the two trains are approaching each other

• Use the formula: Speed of Train A + Speed of Train B = Relative Speed

• Once the relative speed is calculated, the individual speeds of the trains can be determined by subtracting one speed from the relative speed

Indexes in SQL are used to improve query performance by allowing the database to quickly locate rows in a table.

• Indexes should be created on columns frequently used in WHERE, JOIN, and ORDER BY clauses.

• Avoid creating indexes on columns with low selectivity.

• Regularly monitor and maintain indexes to ensure optimal performance.

SOLID principles are a set of guidelines for writing maintainable and scalable code.

• Single Responsibility Principle (SRP) - a class should have only one reason to change

• Open/Closed Principle (OCP) - classes should be open for extension but closed for modification

• Liskov Substitution Principle (LSP) - subclasses should be substitutable for their base classes

• Interface Segregation Principle (ISP) - clients should not be forced to depend on interfaces they do not use

• Dependency Inv...read more

Angular pipes are used to transform data in templates. Types in Angular provide static type checking.

• Angular pipes are used to format and transform data in templates.

• They can be used to filter, sort, and manipulate data before displaying it.

• Pipes can be chained together to perform multiple transformations.

• Types in Angular provide static type checking and help catch errors during development.

• They ensure that variables and function parameters have the correct data types.

HTTP response codes and their troubleshooting scenarios

• HTTP 200 - OK: Successful request

• HTTP 404 - Not Found: Resource not found

• HTTP 500 - Internal Server Error: Server-side error

• HTTP 401 - Unauthorized: Authentication failure

• HTTP 403 - Forbidden: Authorization failure

• HTTP 302 - Found: Redirect to a different URL

• HTTP 503 - Service Unavailable: Server is down or overloaded

We use ELK stack for logging in the project

• We utilize ELK stack (Elasticsearch, Logstash, Kibana) for centralized logging

• Logs are collected, processed, and visualized using these tools

• We have defined log levels and formats for consistency

• Logs are monitored for errors and performance issues

Garbage collector is a mechanism in programming languages that automatically frees up memory occupied by objects that are no longer in use.

• Garbage collector is responsible for managing memory in a program.

• It identifies and frees up memory occupied by objects that are no longer needed.

• Garbage collector uses various algorithms to determine which objects are eligible for garbage collection.

• Common garbage collection algorithms include reference counting, mark and sweep, and gener...read more

Dynamic elements in Selenium can be handled using various techniques like explicit waits, fluent waits, and dynamic xpath.

• Use explicit waits to wait for a specific condition to be met before proceeding with the test

• Use fluent waits to wait for a specific element to be visible or clickable

• Use dynamic xpath to locate elements based on changing attributes or values

Different types of joins are used in SQL to combine rows from two or more tables based on a related column between them.

• INNER JOIN: Returns rows when there is at least one match in both tables.

• LEFT JOIN: Returns all rows from the left table and the matched rows from the right table.

• RIGHT JOIN: Returns all rows from the right table and the matched rows from the left table.

• FULL JOIN: Returns rows when there is a match in one of the tables.

• CROSS JOIN: Returns the Cartesian produ...read more

BDD framework is a software development process that encourages collaboration between developers, QA, and non-technical stakeholders.

• BDD stands for Behavior Driven Development

• Uses plain English to describe the behavior of an application

• Focuses on the behavior of the system rather than implementation details

• Uses tools like Cucumber, JBehave, SpecFlow

• Helps in creating automated tests that are easy to understand by non-technical stakeholders