400+ Interview Questions and Answers

Given an unsorted array, find the K largest elements in non-decreasing order.

• Sort the array in non-decreasing order.

• Return the last K elements of the sorted array.

Public and private IP addresses are used in computer networks. Public IPs are globally unique and accessible from the internet, while private IPs are used within a local network.

• Public IP is assigned by the Internet Service Provider (ISP) and is used to identify a device on the internet.

• Private IP is assigned by a local network administrator and is used to identify a device within a local network.

• Public IPs are globally unique, allowing devices to communicate with each other ...read more

Program to reverse a string without using string function

• Iterate through the string from end to start and append each character to a new string

• Use a loop to swap the first and last characters, then move towards the middle until the entire string is reversed

• Convert the string to a character array, then swap the first and last elements until the entire array is reversed

C is a procedural programming language while C++ is an object-oriented programming language.

• C is a procedural programming language, meaning it focuses on procedures or functions.

• C++ is an extension of C and adds object-oriented features like classes and inheritance.

• C++ supports polymorphism, encapsulation, and abstraction, which C lacks.

• C++ allows the use of standard template library (STL) for data structures and algorithms.

• C++ has exception handling mechanisms, whereas C doe...read more

Keys in a database are unique identifiers used to establish relationships between tables and ensure data integrity.

• Keys are used to uniquely identify records in a database table.

• Primary keys are used to uniquely identify each record in a table.

• Foreign keys establish relationships between tables.

• Keys help enforce data integrity and maintain consistency in the database.

• Examples of keys include primary keys, foreign keys, and unique keys.

Deadlocks are situations where two or more processes are unable to proceed because each is waiting for the other to release a resource.

• Deadlocks occur when multiple processes are stuck in a circular waiting state.

• Prevention techniques include resource allocation strategies, deadlock detection, and avoidance algorithms.

• Examples of prevention techniques are using a resource allocation graph, implementing a banker's algorithm, and employing timeouts and resource preemption.

A message is transferred in OSI layer through a process called encapsulation and decapsulation.

• The message is divided into smaller chunks called packets at the transport layer.

• Each packet is then encapsulated with headers containing necessary information.

• The encapsulated packets are then passed down to the network layer.

• At the network layer, the packets are further encapsulated with network layer headers.

• The encapsulated packets are then passed down to the data link layer.

• At ...read more

Polymorphism is the ability of an object to take on many forms. It allows objects of different classes to be treated as the same type.

• Polymorphism is achieved through method overriding and method overloading.

• It allows for code reusability and flexibility in object-oriented programming.

• Three conditions for polymorphism are inheritance, method overriding, and a common interface or base class.

Prediction uses data analysis and statistical models to forecast future outcomes.

• Prediction involves collecting and analyzing data to identify patterns and trends.

• Statistical models are then used to make predictions based on the identified patterns.

• Predictions can be made for a wide range of applications, such as weather forecasting, stock market trends, and customer behavior.

• Accuracy of predictions can be improved by using machine learning algorithms and incorporating new da...read more

Yes, My Passion Challenge test is a coding competition for software engineers.

• My Passion Challenge test is a coding competition that evaluates the coding skills of software engineers.

• It is designed to test problem-solving abilities, algorithmic thinking, and coding proficiency.

• Participants are given a set of coding challenges to solve within a specified time limit.

• The challenges can range from simple to complex, covering various programming languages and concepts.

• The test ass...read more

The max distance that can be traveled is 15km.

• Each wheel can travel 5km, so with 3 wheels, the total distance is 15km.

• The scooter itself does not limit the distance that can be traveled, only the wheels do.

Classification algorithms can be represented using flow charts.

• Classification algorithms are used to categorize data into different classes.

• Flow charts can be used to represent the decision-making process of classification algorithms.

• Examples of classification algorithms include decision trees, k-nearest neighbors, and support vector machines.

Normalisation reduces data redundancy and improves data integrity in a database.

• Prevents data duplication and inconsistencies

• Simplifies database maintenance and updates

• Improves query performance

• Enforces data integrity and consistency

• Follows best practices for database design

• Examples: breaking down a customer table into separate tables for orders, addresses, and payments

• Examples: creating a separate table for product categories instead of repeating the category name in each pr...read more

Machine learning is a subset of artificial intelligence that enables machines to learn from data without being explicitly programmed.

• It involves training algorithms on large datasets to make predictions or decisions.

• It can be supervised, unsupervised, or semi-supervised.

• Examples include image recognition, natural language processing, and recommendation systems.

Node.js is a server-side JavaScript runtime environment.

• Node.js is built on top of the V8 JavaScript engine from Google Chrome.

• It allows developers to write server-side code in JavaScript.

• Node.js has a non-blocking I/O model, making it efficient for handling large amounts of data.

• Node.js has a vast library of modules available through npm (Node Package Manager).

Sorting a file within a range

• Use a sorting algorithm like quicksort or mergesort

• Read the file and store the data in an array or list

• Sort the array or list within the given range

• Write the sorted data back to the file

Default values of variables are the initial values assigned to variables if no value is explicitly provided.

• Default value for integer variables is 0

• Default value for floating point variables is 0.0

• Default value for boolean variables is false

• Default value for string variables is null

• Default value for arrays is null

Java is platform independent while C++ is not.

• Java code is compiled into bytecode which can run on any platform with a JVM, while C++ code needs to be compiled separately for each platform.

• Java has automatic memory management through garbage collection, while C++ requires manual memory management.

• Java has built-in support for multithreading, while C++ requires external libraries.

• Java has a simpler syntax and is easier to learn than C++.

• C++ allows for low-level memory manipula...read more

Function overloading is having multiple functions with the same name but different parameters. Function overriding is having a function in a subclass with the same name and parameters as a function in the superclass.

• Function overloading is a compile-time polymorphism concept.

• Function overriding is a runtime polymorphism concept.

• Function overloading is used to provide different implementations of the same function for different input parameters.

• Function overriding is used to p...read more

The program prints a star pattern using asterisks and spaces.

• Use nested loops to iterate through rows and columns.

• Determine the number of asterisks and spaces to print in each row.

• Use conditional statements to decide when to print an asterisk or a space.

let, var, and const are all used to declare variables in JavaScript, but they have different scoping rules and behaviors.

• let and const were introduced in ES6, while var has been around since the beginning of JavaScript.

• let and const are block-scoped, while var is function-scoped.

• Variables declared with const cannot be reassigned, while let and var can be.

• const variables must be initialized when they are declared, while let and var can be declared without initialization.

• Exampl...read more

Find the second largest element from an integer array in a single traversal

• Initialize two variables to store the largest and second largest elements

• Traverse the array and update the variables accordingly

• Return the second largest element

Demonstrate outer join using SQL query

• Use LEFT OUTER JOIN or RIGHT OUTER JOIN to include all records from one table and matching records from another table

• Use the ON keyword to specify the join condition

• Use COALESCE function to handle NULL values in the result set

The language used in rocket launching software is typically Ada.

• Ada is a high-level programming language designed for embedded systems and real-time applications.

• Ada is known for its strong typing and safety features, making it suitable for critical systems like rocket launching software.

Banker's algorithm is a resource allocation and deadlock avoidance algorithm used in operating systems.

• It is used to prevent deadlocks by ensuring that the system never enters an unsafe state.

• It works by simulating the allocation of resources and checking if the system will remain in a safe state.

• It requires knowledge of the maximum resource needs of each process and the currently available resources.

• If a request for resources would result in an unsafe state, the request is d...read more

Interoperability in inheritance and polymorphism allows objects of different classes to be used interchangeably.

• Inheritance allows a subclass to inherit properties and methods from a superclass.

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

• Interoperability between inheritance and polymorphism allows objects of different classes to be used interchangeably.

• For example, a subclass can be used wherever a superclass is expected, an...read more

C++ is a high-level programming language with features like object-oriented programming, templates, and memory management.

• C++ supports object-oriented programming concepts like encapsulation, inheritance, and polymorphism.

• Templates allow generic programming and code reusability.

• C++ provides low-level memory manipulation through pointers.

• Standard Template Library (STL) provides a collection of classes and functions for data structures and algorithms.

• C++ supports operator overl...read more

Issues in cloud include security, downtime, vendor lock-in, and data privacy.

• Security concerns such as data breaches and unauthorized access

• Downtime and service interruptions affecting business operations

• Vendor lock-in and limited flexibility in choosing cloud providers

• Data privacy and compliance with regulations such as GDPR and HIPAA

The data structure implemented in an elevator is a queue.

• Elevator requests are added to the queue in the order they are received.

• The elevator serves requests in a first-come, first-served manner.

• Once a request is completed, it is removed from the queue.

• Example: If someone on the 5th floor requests the elevator, their request is added to the queue and the elevator will serve it after completing any previous requests.

Implementing binary search on a linked list

• Find the middle element of the linked list

• Compare the middle element with the search key

• If the middle element is greater than the search key, search in the left half of the linked list

• If the middle element is less than the search key, search in the right half of the linked list

• Repeat until the search key is found or the entire linked list is traversed

Encapsulation is bundling data and methods together, while abstraction is hiding the implementation details.

• Encapsulation combines data and methods into a single unit (class).

• Abstraction hides the complex implementation details and only shows the necessary features.

• Encapsulation provides data security by restricting access to certain data members.

• Abstraction allows for easier maintenance and modification of code.

• Example: Encapsulation - a class with private data members and p...read more

The flow diagram of my final year project showcases the step-by-step process of its execution.

• The flow diagram illustrates the sequence of activities and their dependencies.

• It helps in understanding the overall structure and logic of the project.

• Each step in the diagram represents a specific task or action.

• Arrows indicate the flow of control or data between different steps.

• Decision points are represented by diamond-shaped symbols.

• Example: Start -> Input Data -> Process Data -...read more

I have worked on building recommendation systems for e-commerce websites and streaming platforms.

• Implemented collaborative filtering algorithms to recommend products based on user behavior

• Utilized content-based filtering to suggest movies or TV shows based on user preferences

• Developed hybrid recommendation systems combining collaborative and content-based filtering techniques

Express.js is a popular Node.js web framework used for building web applications. Body-parser is a middleware used to parse incoming request bodies.

• Express.js is a minimal and flexible Node.js web application framework that provides a robust set of features for web and mobile applications.

• It provides a way to handle HTTP requests and responses, routing, middleware, and more.

• Body-parser is a middleware used to parse incoming request bodies in a middleware before your handlers,...read more

Scopes in JavaScript determine the accessibility of variables and functions.

• Global scope: variables and functions declared outside any function are accessible globally

• Local scope: variables and functions declared inside a function are only accessible within that function

• Block scope: variables declared with let and const are only accessible within the block they are declared in

• Function scope: variables declared with var are accessible within the function they are declared in

Find 2nd largest element in an array with repeated elements in O(n) complexity.

• Traverse the array once and keep track of the largest and second largest elements.

• If the current element is greater than the largest element, update both largest and second largest elements.

• If the current element is between the largest and second largest elements, update only the second largest element.

Big Data refers to large and complex data sets that cannot be processed using traditional data processing methods.

• Big Data is characterized by the 3Vs - Volume, Velocity, and Variety.

• It requires specialized tools and technologies such as Hadoop, Spark, and NoSQL databases.

• Examples of Big Data include social media data, sensor data, and financial market data.

Transaction logs are records of all the changes made to a database or file system.

• They help in recovering data in case of system failure or errors.

• They provide a history of all the transactions made to the database or file system.

• They are used for auditing and compliance purposes.

• Examples include SQL Server transaction logs, file system transaction logs, etc.

Hands-on experience with SQL queries for creating and manipulating tables and table elements.

• Use CREATE TABLE statement to create a new table

• Use ALTER TABLE statement to add, modify, or delete columns in a table

• Use INSERT INTO statement to add new rows of data into a table

• Use UPDATE statement to modify existing data in a table

• Use DELETE statement to remove rows from a table

Answering questions related to Java 8 features, microservices, RDBMS vs NoSQL DB, defect severity and priority, defect density and slippage, handling difficult clients and conflicts within the team.

• Java 8 features include lambda expressions, streams, functional interfaces, and default methods.

• Disadvantages of microservices include increased complexity, difficulty in testing, and potential communication issues.

• RDBMS is a relational database management system that uses tables w...read more

Python compiles source code to bytecode for faster execution, stored in .pyc files.

• Python interpreter compiles source code to bytecode before execution

• Bytecode is platform-independent and faster to execute than source code

• Compiled bytecode is stored in .pyc files for future use and faster startup time

• If source code is modified, .pyc files are automatically recompiled

Fill the 3 gallon jug, pour it into the 5 gallon jug, fill the 3 gallon jug again, pour it into the 5 gallon jug until it is full, leaving 1 gallon in the 3 gallon jug.

• Fill the 3 gallon jug

• Pour the 3 gallon jug into the 5 gallon jug

• Fill the 3 gallon jug again

• Pour the 3 gallon jug into the 5 gallon jug until it is full

• The 4 gallon jug will have 1 gallon of water

Cloud computing refers to the delivery of computing services over the internet.

• Cloud computing allows users to access data and applications from anywhere with an internet connection

• It eliminates the need for physical servers and hardware, reducing costs and increasing scalability

• Examples include Amazon Web Services, Microsoft Azure, and Google Cloud Platform

Precompilation unit is a compiled code that can be reused by multiple source files.

• Precompilation unit is created by the compiler from the source code.

• It contains the compiled code of header files and other dependencies.

• It can be reused by multiple source files, reducing compilation time.

• It is also known as precompiled header or PCH.

• Example: stdafx.h in Visual Studio is a precompiled header file.

Thrashing is a phenomenon in computer systems where excessive swapping of data between RAM and virtual memory occurs.

• Occurs when a computer spends more time swapping data between RAM and virtual memory than executing actual tasks

• Can be caused by insufficient RAM or poorly optimized programs

• Can lead to a significant decrease in system performance

• Example: A computer running multiple memory-intensive programs simultaneously may experience thrashing

SQL query to find duplicates, reversing a linked list, real-life examples of stacks and queues

• To find duplicates in SQL, use GROUP BY and HAVING clauses

• To reverse a linked list, iterate through the list and change the pointers

• Stacks: back button in a web browser, undo feature in text editors

• Queues: waiting in line at a grocery store, printer queue for printing documents

Interview questions for Project Lead position covering API testing, HTTP error codes, performance testing, Java, authentication, Swagger, AWS, and project-related questions.

• API testing involves testing the functionality, reliability, performance, and security of APIs.

• HTTP error codes are status codes returned by a server to indicate the status of a request.

• APIs can be tested using tools like Postman, SoapUI, and JMeter.

• Types of APIs include REST, SOAP, and GraphQL.

• Java and OO...read more

Closure is a function that has access to variables in its outer scope, even after the outer function has returned.

• Closure is created when a function is defined inside another function.

• The inner function can access variables in the outer function, even after the outer function has returned.

• Closure can be used to create private variables and functions in JavaScript.

• Example: function outer() { var x = 10; function inner() { console.log(x); } return inner; } var closure = outer()...read more

Implementing a conditional hierarchical model for a Java class.

• Create a Java class with multiple levels of hierarchy

• Implement conditional statements to control the behavior of the class based on certain conditions

• Use if-else or switch statements to define different actions for different conditions

• Consider using interfaces or abstract classes for better abstraction and modularity

Callback hell is a situation where nested callbacks make code unreadable. Promises are a solution to this problem.

• Callback hell occurs when there are too many nested callbacks in asynchronous code

• It makes the code difficult to read and maintain

• Promises are a way to handle asynchronous operations without nested callbacks

• Promises can be used to chain multiple asynchronous operations together

• Promises have a resolve and reject function to handle success and failure respectively

Many-to-many relationship in Hibernate without common columns

• Create a third table with foreign keys to both tables

• Use @ManyToMany annotation in both entity classes

• Specify the join table name and column names in @JoinTable annotation

Encapsulation is bundling data and methods together, abstraction is hiding implementation details, and polymorphism allows objects to be treated as instances of their parent class.

• Encapsulation involves bundling data and methods within a class to restrict access from outside.

• Abstraction involves hiding the implementation details of a class and only showing the necessary features.

• Polymorphism allows objects to be treated as instances of their parent class, enabling flexibility...read more

Copy assignment operator is a special member function in C++ that allows one object to be assigned the values of another object of the same class.

• Copy assignment operator is denoted by the = operator.

• It is used to copy the values of one object into another object of the same class.

• It is automatically generated by the compiler if not explicitly defined.

• Example: MyClass obj1; MyClass obj2; obj2 = obj1; // Copy assignment operator is called

Query to find the second highest salary in a table.

• Use the MAX() function to find the highest salary.

• Use the WHERE clause to exclude the highest salary from the result.

• Use the MAX() function again to find the second highest salary.

Binary Search Tree

• A binary tree where each node has at most two children

• Left child is less than parent, right child is greater

• Allows for efficient searching, insertion, and deletion

Use the len() function to check the length of the data frame.

• Use len() function to get the number of rows in the data frame.

• If the length is 0, then the data frame is empty.

• Example: if len(df) == 0: print('Data frame is empty')

A constructor in C++ is a special member function that is automatically called when an object is created.

• Constructors have the same name as the class and do not have a return type.

• They can be used to initialize the object's data members.

• Default constructors are automatically generated if no constructor is defined.

• Parameterized constructors can be defined to accept arguments during object creation.

The first 50 prime numbers are...

• Start with 2, the first prime number

• Check each odd number greater than 2

• Use trial division to check if a number is prime

• Stop when you have found 50 prime numbers

Find second largest integer in an array without sorting or using collections.

• Iterate through array and keep track of largest and second largest integers.

• Compare each element with current largest and second largest integers.

• Return second largest integer.

Code for half pyramid using numbers

• Use nested loops to print the numbers in each row

• The number of columns in each row should be equal to the row number

• Start the loop from 1 and go up to the desired number of rows

Two programming code examples in any language

• Example 1: Python - print('Hello, World!')

• Example 2: Java - System.out.println('Hello, World!')

Passport.js is an authentication middleware for Node.js.

• Passport.js provides a simple way to authenticate users with various authentication strategies such as local, OAuth, OpenID, etc.

• It is highly customizable and can be integrated with any Node.js web application framework.

• Passport.js maintains user sessions and provides a consistent API for authentication across different strategies.

• Example: Using Passport.js with Express.js to authenticate users with Google OAuth2.

• Example...read more

Repartition increases or decreases the number of partitions in a DataFrame, while Coalesce only decreases the number of partitions.

• Repartition can increase or decrease the number of partitions in a DataFrame, leading to a shuffle of data across the cluster.

• Coalesce only decreases the number of partitions in a DataFrame without performing a full shuffle, making it more efficient than repartition.

• Repartition is typically used when there is a need to increase the number of parti...read more

Virtualization in C++ is the process of creating a virtual version of a class or function to allow for polymorphism and dynamic binding.

• Virtualization in C++ is achieved through the use of virtual functions and inheritance.

• Virtual functions are declared in a base class and overridden in derived classes to provide different implementations.

• Virtualization allows for polymorphism, where a pointer to a base class can point to objects of derived classes.

• Dynamic binding is used to ...read more

Smart pointers are objects that act like pointers but provide automatic memory management.

• Smart pointers help prevent memory leaks by automatically deallocating memory when no longer needed.

• Examples include unique_ptr, shared_ptr, and weak_ptr in C++.

• They provide better memory safety compared to raw pointers.

A tree is a hierarchical data structure with nodes connected by edges. A queue is a linear data structure that follows the FIFO principle.

• A tree can be implemented using linked lists or arrays.

• A queue can be implemented using arrays or linked lists.

• In a tree, each node can have multiple child nodes.

• In a queue, elements are added at the rear and removed from the front.

• Both data structures are commonly used in computer science and have various applications.

OOP stands for Object-Oriented Programming. Sorting the list for finding two lowest elements may not be optimal. ACID properties are atomicity, consistency, isolation, and durability.

• OOP is a programming paradigm based on the concept of objects, which can contain data in the form of fields and code in the form of procedures.

• Sorting the list to find two lowest elements may not be optimal as it has a time complexity of O(n log n). A more efficient solution would be to iterate t...read more

Media query for 3 divs in row for desktop and column for mobile view

• Use min-width and max-width to target desktop and mobile views respectively

• Set display property to flex and flex-wrap to wrap for desktop view

• Set display property to block for mobile view

In Apex, security is enforced by default. If a user doesn't have access to a field, they won't be able to query it.

• In Apex, security is enforced by default, meaning that users can only access data they have permission to see.

• If a user doesn't have access to the Phone field in the Account object, they won't be able to query it even with WITH_SECURITY_ENFORCED.

• The SELECT id, Name, Phone from Account WITH_SECURITY_ENFORCED query will only return the id and Name fields for users ...read more

Event loop is a mechanism that allows JavaScript to perform non-blocking I/O operations.

• Event loop is a loop that constantly checks the message queue and executes the next message if there is any.

• Phases are the different stages of the event loop, such as timers, I/O callbacks, idle, and poll.

• Event loop is crucial for Node.js to handle multiple requests simultaneously without blocking the main thread.

• Example: setTimeout() function is added to the timer phase and executed after...read more

Find indexes of two values in an array whose sum is 8 or a dynamic value

• Iterate through the array and store the indexes of each element in a dictionary with the difference between the target sum and the element as the key

• Check if the current element exists in the dictionary, if so, return the indexes of the two elements

• Handle cases where the target sum is dynamic by replacing 8 with a variable

I can provide solutions for pattern codes in software engineering interviews.

• Understand the pattern and break it down into smaller components

• Use loops and conditional statements to generate the desired pattern

• Test the code with different inputs to ensure it works correctly

A program to print patterns using arrays of strings.

• Create an array of strings to hold the pattern

• Use loops to fill the array with the desired pattern

• Print the array to display the pattern

PUT method updates data if available, else returns success with no changes.

• PUT method updates the resource if it exists, else creates a new resource

• If no data is provided, the server returns a success response with no changes made

• Example: PUT /users/1 with empty body will return success with no changes if user with id 1 exists

Reverse a string using SQL and Python codes.

• In SQL, use the REVERSE function to reverse a string.

• In Python, use slicing with a step of -1 to reverse a string.

The OSI model has 7 layers. OSI or TCP/UDP depends on the application. OSI is used for theoretical understanding while TCP/UDP is used for practical implementation.

• The 7 layers of OSI model are Physical, Data Link, Network, Transport, Session, Presentation, and Application.

• OSI model is used for theoretical understanding of networking concepts.

• TCP/UDP are used for practical implementation of networking protocols.

• TCP is used for reliable data transfer while UDP is used for fast...read more

Functional testing is a type of testing that verifies if the software meets the functional requirements.

• It is a black-box testing technique

• It focuses on the external behavior of the software

• It ensures that the software functions as expected

• Types of functional testing include unit testing, integration testing, system testing, acceptance testing, and regression testing

Microservices are a software architecture design where applications are broken down into smaller, independent services that communicate with each other through APIs.

• Microservices are designed to be small, focused, and independently deployable services.

• Each microservice typically performs a single function or task within the application.

• Microservices communicate with each other through APIs, often using lightweight protocols like HTTP or messaging queues.

• Load balancing in micr...read more

The task is to count the occurrences of each character in a given string.

• Iterate through the string and use a hashmap to store the count of each character

• Convert the string to an array of characters for easier manipulation

• Handle edge cases like empty string or null input

• Consider using built-in functions like HashMap in Java or Counter in Python

Use a hashmap to store word frequencies in a sentence.

• Split the sentence into words using a space delimiter.

• Create a hashmap to store word frequencies.

• Iterate through the words and update the frequencies in the hashmap.

• Return the hashmap with word frequencies.

HTTP is unsecured while HTTPS is secured with SSL/TLS encryption.

• HTTP stands for Hypertext Transfer Protocol while HTTPS stands for Hypertext Transfer Protocol Secure.

• HTTP operates on port 80 while HTTPS operates on port 443.

• HTTP is vulnerable to attacks while HTTPS is secure due to SSL/TLS encryption.

• HTTPS is indicated by a padlock icon in the browser's address bar.

• HTTPS is used for secure online transactions such as online banking, e-commerce, etc.

Difference between sort and sorted, dump vs dumps, load vs loads etc.

• sort() is a method of list object while sorted() is a built-in function

• dump() serializes an object to a file while dumps() serializes to a string

• load() deserializes an object from a file while loads() deserializes from a string

Explaining request mapping annotation syntax and usage in Java development

• RequestMapping annotation is used to map HTTP requests to specific methods in a controller class

• It can be used to specify the URL path, HTTP method, request parameters, headers, and more

• Example: @RequestMapping(value = '/users', method = RequestMethod.GET)

• This maps a GET request to the '/users' URL path

Extent report can be implemented by adding the extent report dependency, creating an instance of ExtentReports class, and using ExtentTest class to create test logs.

• Add the extent report dependency in the project's pom.xml file

• Create an instance of ExtentReports class in the @BeforeSuite method

• Create an instance of ExtentTest class in the @BeforeMethod method

• Use ExtentTest class to log test steps and results

• Generate the report using the flush() method in the @AfterSuite metho...read more

Use @PostConstruct annotation or implement CommandLineRunner interface

• Use @PostConstruct annotation on a method that needs to be executed on startup

• Implement CommandLineRunner interface and override run() method

• Add the code that needs to be executed on startup in the method annotated with @PostConstruct or in the run() method

• Example: @PostConstruct public void init() { //code to be executed on startup }

• Example: public class MyApp implements CommandLineRunner { public void run...read more

Cores and worker nodes are decided based on the workload requirements and scalability needs of the data processing system.

• Consider the size and complexity of the data being processed

• Evaluate the processing speed and memory requirements of the tasks

• Take into account the parallelism and concurrency needed for efficient data processing

• Monitor the system performance and adjust cores and worker nodes as needed

Function hoisting is a JavaScript behavior where function declarations are moved to the top of their scope.

• Function declarations are moved to the top of their scope during the compilation phase.

• Function expressions are not hoisted.

• Hoisting can lead to unexpected behavior and bugs if not understood properly.

Microservices can communicate through synchronous or asynchronous protocols like REST, gRPC, or message brokers.

• Use RESTful APIs for synchronous communication

• Use message brokers like Kafka or RabbitMQ for asynchronous communication

• gRPC can be used for high-performance synchronous communication

• API Gateway can be used to manage communication between microservices

• Consider using service mesh like Istio or Linkerd for more advanced communication needs

Use Spark and SQL to find the top 5 countries with the highest population.

• Use Spark to load the data and perform data processing.

• Use SQL queries to group by country and sum the population.

• Order the results in descending order and limit to top 5.

• Example: SELECT country, SUM(population) AS total_population FROM table_name GROUP BY country ORDER BY total_population DESC LIMIT 5

You can change the create date while uploading records through Data Loader by enabling the 'Allow Insert' option.

• Enable 'Allow Insert' option in Data Loader settings

• Map the 'Created Date' field in the mapping file to the desired date/time value

• Ensure the user has the necessary permissions to change the create date

Wire method in Salesforce is used to fetch data from Apex controller to Lightning Web Component. Adding records inside wire method in JS file involves using imperative Apex to create records.

• Use @wire decorator in Lightning Web Component JS file to call an Apex method

• Inside the wire method, use imperative Apex to create records by calling the createRecord method from the Lightning Data Service

• Pass the record data as parameters to the createRecord method

Shuffling is the process of redistributing data across partitions in a distributed computing environment.

• Shuffling is necessary when data needs to be grouped or aggregated across different partitions.

• It can be handled efficiently by minimizing the amount of data being shuffled and optimizing the partitioning strategy.

• Techniques like partitioning, combiners, and reducers can help reduce the amount of shuffling in MapReduce jobs.