20+ ClassMonitor Interview Questions and Answers

Spark accumulators are used to accumulate values across multiple tasks in a distributed manner.

• Accumulators are used to accumulate values across multiple tasks in a distributed manner

• They are used to implement counters and sums in Spark

• Accumulators are read-only variables that can only be updated by an associative and commutative operation

• Partitioning is the process of dividing a large dataset into smaller, more manageable pieces

• Bucketing is a technique used to group data int...read more

Virtual functions are functions that can be overridden in derived classes. vTable is a lookup table used to resolve virtual function calls.

• Virtual functions allow polymorphism and dynamic binding

• vTable is a table of function pointers used to resolve virtual function calls

• vPtr is a pointer to the vTable of an object

• Smart pointers are objects that manage the lifetime of dynamically allocated memory

• Types of smart pointers include unique_ptr, shared_ptr, and weak_ptr

• Exception han...read more

String intern is a method in Java that returns a canonical representation of a string object.

• String intern() method returns a canonical representation for the string object.

• If a string with the same contents is already in the string pool, then it returns the reference to that string.

• If not present, it adds the string to the pool and returns the reference.

Threads are lightweight processes within a single process, sharing memory space. Processes are independent instances of a program.

• Threads share memory space, making communication between threads faster and more efficient.

• Processes have their own memory space, making them more isolated and secure.

• Threads are faster to create and terminate compared to processes.

• Processes are more stable and reliable, as a crash in one process does not affect others.

• Threads are suitable for task...read more

Transaction management in Java involves managing database transactions to ensure data integrity and consistency.

• Use JDBC or JPA for transaction management

• Begin a transaction with 'beginTransaction()' method

• Commit the transaction with 'commit()' method

• Rollback the transaction with 'rollback()' method

Api design using Spring boot involves creating RESTful APIs with Spring framework for efficient communication between client and server.

• Use @RestController annotation to define RESTful web services

• Utilize @RequestMapping annotation to map HTTP requests to specific handler methods

• Implement request and response bodies using @RequestBody and @ResponseBody annotations

• Leverage Spring Boot's auto-configuration and embedded server for easy deployment

Design patterns are reusable solutions to common problems in software design.

• Design patterns help in creating flexible, maintainable, and scalable software.

• Some common design patterns include Singleton, Factory, Observer, and Strategy.

• Each design pattern has a specific purpose and can be applied in different scenarios.

• Understanding design patterns can improve code quality and make development more efficient.

SOLID principles are a set of five design principles that help in creating maintainable and scalable software applications.

• S - Single Responsibility Principle (SRP)

• O - Open-Closed Principle (OCP)

• L - Liskov Substitution Principle (LSP)

• I - Interface Segregation Principle (ISP)

• D - Dependency Inversion Principle (DIP)

HashMap is a data structure that stores key-value pairs and uses hashing to efficiently retrieve values.

• HashMap internally uses an array of linked lists to store key-value pairs.

• When a key-value pair is added, the key is hashed to determine the index in the array where it will be stored.

• If multiple keys hash to the same index, a collision occurs and the key-value pairs are stored in a linked list at that index.

• To retrieve a value, the key is hashed again to find the index and...read more

Object-oriented programming principles for organizing and designing code.

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

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

• Polymorphism: Ability for objects to take on multiple forms or types.

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

Currently working on developing a web-based project management tool for a tech startup.

• Utilizing React for front-end development

• Implementing Node.js for back-end functionality

• Integrating MongoDB for database management