100+ Delhi Heart & Lung Institute Interview Questions and Answers

Exception is a runtime error that can be handled, while error is a severe issue that cannot be handled.

• Exceptions are caused by the program logic, while errors are caused by external factors like hardware failure or network issues.

• Exceptions can be caught and handled using try-catch blocks, while errors require fixing the underlying issue.

• Example of exception: NullPointerException. Example of error: Out of Memory Error.

• To solve errors in code deployment, identify the root cau...read more

Checked and unchecked exceptions differ in their handling and requirement for try-catch blocks.

• Checked exceptions are checked at compile time and require handling in a try-catch block.

• Unchecked exceptions are not checked at compile time and do not require handling.

• Examples of checked exceptions include IOException and SQLException.

• Examples of unchecked exceptions include NullPointerException and ArrayIndexOutOfBoundsException.

Python is a high-level, interpreted programming language. Java is a compiled language.

• Python is dynamically typed while Java is statically typed

• Python has simpler syntax and is easier to learn than Java

• Java is faster and more efficient than Python

• Python is better suited for data analysis and machine learning while Java is better for enterprise applications

• Python has a larger community and more libraries than Java

By checking the server logs or using tools like 'ps' command or 'netstat' command.

• Check server logs for information on which server the application is running on.

• Use 'ps' command to list running processes and identify the server.

• Use 'netstat' command to check network connections and identify the server.

OOPs is a programming paradigm that focuses on objects and their interactions. It includes concepts like inheritance, polymorphism, and encapsulation.

• Inheritance: A child inherits traits from their parents. Similarly, a subclass can inherit properties and methods from a superclass.

• Polymorphism: A person can have different roles in different situations. Similarly, an object can have different forms or behaviors depending on the context.

• Encapsulation: A person's internal organs...read more

Currently using Agile project management method.

• We follow Scrum framework for our software development process.

• We have daily stand-up meetings to discuss progress and plan for the day.

• We use JIRA for tracking tasks and issues.

• We prioritize tasks based on customer feedback and business value.

• We continuously improve our process through retrospectives.

Collections are used to store and manipulate groups of objects in memory.

• Collections provide efficient access and manipulation of data.

• They allow for easy iteration and sorting of data.

• Examples include ArrayList, HashMap, and LinkedList.

• Collections are commonly used in data structures and algorithms.

• They are essential for managing large amounts of data in software development.

Design patterns are reusable solutions to common software problems. They provide a standard way to solve similar problems.

• Creational patterns: Singleton, Factory, Abstract Factory, Builder, Prototype

• Structural patterns: Adapter, Bridge, Composite, Decorator, Facade, Flyweight, Proxy

• Behavioral patterns: Chain of Responsibility, Command, Interpreter, Iterator, Mediator, Memento, Observer, State, Strategy, Template Method, Visitor

Factorial can be calculated using a loop by multiplying numbers from 1 to n.

• Initialize a variable to 1

• Use a loop to multiply the variable with numbers from 1 to n

• Return the variable

Spring Boot is preferred for rapid development and microservices, while Spring MVC is used for traditional web applications.

• Spring Boot is preferred for rapid development of microservices due to its convention over configuration approach.

• Spring MVC is used for traditional web applications where more customization and configuration is required.

• Spring Boot includes embedded servers like Tomcat, Jetty, and Undertow, making it easier to deploy standalone applications.

• Spring MVC r...read more

Views in MySQL database provide a virtual table that can be used to simplify complex queries.

• Views can be used to hide complexity of a query by creating a virtual table that can be queried like a regular table.

• They can also be used to restrict access to certain columns or rows of a table.

• Views can improve performance by reducing the amount of data that needs to be retrieved from the database.

• They can also be used to simplify the process of joining multiple tables.

• Example: A v...read more

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

• OOP is a way of organizing and designing code around objects

• It emphasizes encapsulation, inheritance, and polymorphism

• Encapsulation is the practice of hiding data and methods within an object

• Inheritance allows objects to inherit properties and methods from a parent object

• Polymorphism allows objects to take on multiple forms or behaviors

• Examples of OOP languages include Jav...read more

Sorting data in SQL queries

• Use ORDER BY clause to sort data in ascending or descending order

• Specify the column name to sort by

• Can sort by multiple columns

• Can use functions like COUNT, AVG, etc. in ORDER BY clause

• Example: SELECT * FROM table_name ORDER BY column_name ASC/DESC

• Example: SELECT * FROM table_name ORDER BY column1 ASC, column2 DESC

Java program to find palindrome

• Take input string from user

• Convert the string to lowercase

• Reverse the string

• Compare the original and reversed string

• If they are equal, then it is a palindrome

The main component to work on concurrent program in EBS is Concurrent Manager.

• Concurrent Manager is responsible for managing and executing concurrent programs in Oracle E-Business Suite (EBS).

• It controls the scheduling, prioritization, and execution of concurrent requests.

• Concurrent Manager monitors the status of concurrent programs and manages resources to ensure efficient processing.

• It provides a centralized control point for managing concurrent processing in EBS.

• Examples o...read more

Python is interpreted and easy due to its dynamic nature and simple syntax.

• Python code is executed line by line, making it easy to debug and test.

• Python has a simple syntax that is easy to read and write.

• Python is dynamically typed, meaning that variables can change types during runtime.

• Python has a large standard library and many third-party modules, making it easy to accomplish complex tasks.

• Python supports object-oriented, functional, and procedural programming paradigms.

There are different types of interfaces in Java, features of Java 8 include lambda expressions and streams, and the current version is Java 15.

• Types of interfaces in Java include normal interfaces, functional interfaces, and marker interfaces.

• Features of Java 8 include lambda expressions for functional programming, streams for processing sequences of elements, and default methods in interfaces.

• Current version of Java is Java 15, released in September 2020.

Encapsulation is hiding implementation details while abstraction is hiding unnecessary details.

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

• Abstraction is achieved through abstract classes and interfaces.

• Encapsulation is used to protect data from outside interference.

• Abstraction is used to simplify complex systems by breaking them down into smaller, more manageable parts.

• Example of encapsulation: Getters and setters in a class.

• Example...read more

Yes, I have 3 years of work experience in backend technologies including Java, Spring Boot, and SQL databases.

• Worked with Java for backend development

• Experience with Spring Boot framework

• Proficient in working with SQL databases like MySQL and PostgreSQL

Software configuration management is the process of tracking and controlling changes made to software throughout its lifecycle.

• It involves version control, build management, and release management.

• It ensures that changes are made in a controlled and systematic manner.

• Examples include Git, SVN, and Jenkins.

• It helps to maintain the integrity and quality of the software.

• It is essential for collaboration among team members working on the same project.

Data can be passed from COBOL to JCL using SYSIN DD * or SYSIN DD DUMMY.

• Use SYSIN DD * to pass data as input to JCL

• Use SYSIN DD DUMMY to pass data as output from COBOL to JCL

• Data can also be passed using PARM parameter in JCL

Use a build tool like Webpack to combine and bundle multiple JavaScript and CSS files for faster loading.

• Use a build tool like Webpack, Gulp, or Grunt to combine multiple JavaScript and CSS files into a single file.

• Minify and optimize the combined file to reduce its size and improve loading speed.

• Utilize techniques like code splitting to load only the necessary code for each page.

• Consider using a content delivery network (CDN) to further optimize loading times.

Java is a high-level programming language known for its platform independence and object-oriented approach.

• Java is a general-purpose programming language.

• It was developed by Sun Microsystems and released in 1995.

• Java programs are compiled into bytecode that can run on any Java Virtual Machine (JVM).

• JDK (Java Development Kit) is a software development environment that includes tools for developing, debugging, and monitoring Java applications.

• JRE (Java Runtime Environment) is a...read more

Yes, multiple constructors can be defined in a single class.

• Constructors are used to initialize objects of a class.

• Multiple constructors can have different parameters.

• Overloading is used to differentiate between constructors.

• Example: public MyClass(int x) { } and public MyClass(int x, int y) { }

Operators in JavaScript are symbols that perform operations on variables and values.

• Arithmetic operators perform mathematical operations (+, -, *, /)

• Comparison operators compare values (==, !=, >, <)

• Logical operators combine multiple conditions (&&, ||, !)

• Assignment operators assign values to variables (=, +=, -=)

• Unary operators operate on a single operand (++, --)

The main method syntax is a standard entry point for Java programs.

• The main method must be declared as public, static, and void.

• The method name must be 'main'.

• The method must accept an array of strings as an argument.

• The method must be defined within a class.

• Example: public static void main(String[] args) { }

Master layout is a template for a webpage while partial view is a reusable component of a webpage.

• Master layout defines the overall structure of a webpage

• Partial view is a reusable component that can be used in multiple pages

• Master layout can contain multiple partial views

• Partial view can be used to display common content like header, footer, etc.

• Example: Master layout can have a partial view for header and footer which can be used in multiple pages

Tuple is immutable and ordered while list is mutable and ordered.

• Tuple uses parentheses while list uses square brackets.

• Tuple is faster than list for accessing elements.

• Tuple is used for fixed data while list is used for dynamic data.

• Tuple can be used as keys in dictionaries while list cannot.

• Example of tuple: my_tuple = (1, 2, 3)

• Example of list: my_list = [1, 2, 3]

Use regular expressions to validate email addresses.

• Check for the presence of '@' symbol

• Ensure that there is at least one character before and after '@'

• Check for the presence of a period '.' after the '@' symbol

• Ensure that there is at least one character after the period

Triggers in Salesforce are used to perform automated actions before or after records are inserted, updated, or deleted.

• Triggers are Apex scripts that are executed before or after specific data manipulation language (DML) events occur in Salesforce.

• They can be used to perform tasks such as validating data, updating related records, or sending email notifications.

• Triggers can be written for different objects in Salesforce, such as Accounts, Contacts, or Opportunities.

• They are e...read more

Implementing AI ML in college requires curriculum updates, faculty training, and access to resources.

• Update the curriculum to include AI and ML courses

• Train faculty members on AI and ML concepts and tools

• Provide access to resources such as high-performance computing systems and datasets

• Encourage research and projects in AI and ML

• Organize workshops, seminars, and hackathons to promote AI and ML learning

• Collaborate with industry experts and companies for internships and guest l...read more

A router is a networking device that forwards data packets between computer networks. A switch is a networking device that connects devices within a network.

• A router operates at the network layer (Layer 3) of the OSI model and uses IP addresses to route packets.

• Routers are used to connect multiple networks together, such as connecting a home network to the internet.

• Routers can determine the best path for data packets to reach their destination.

• A switch operates at the data li...read more

Abstract class is a class that cannot be instantiated, List is a collection of objects, SQL is a language used to manage databases, ADO.net is a framework for accessing databases.

• Abstract class is used as a base class for other classes

• List is a generic collection of objects

• SQL is used to create, modify, and query databases

• ADO.net provides a set of classes for accessing databases

• Example: abstract class Animal { public abstract void MakeSound(); }

• Example: List names = new List(...read more

React is a JavaScript library for building user interfaces.

• React allows developers to create reusable UI components.

• It uses a virtual DOM for efficient rendering.

• React is maintained by Facebook and a community of developers.

• React can be used to build single-page applications.

• React Native allows for building mobile applications using React.

Different types of cursors include implicit, explicit, forward-only, static, and keyset-driven cursors.

• Implicit cursors are automatically created by the database management system and are used for single-row queries.

• Explicit cursors are declared by the programmer and provide more control over the result set.

• Forward-only cursors allow navigating through the result set in a forward direction only.

• Static cursors create a temporary copy of the result set, allowing changes to the ...read more

Answering questions on Exceptions and String equality in Java

• Exceptions are errors that occur during program execution

• Java has a try-catch block to handle exceptions

• String equality can be checked using the equals() method

• The == operator checks if two strings have the same memory address

• String comparison is case-sensitive by default

To check Java version, use command prompt/terminal and type 'java -version'.

• Open command prompt/terminal

• Type 'java -version'

• Press enter

• The installed Java version will be displayed

Truncate removes all data from a table while delete removes specific rows.

• Truncate is faster than delete as it doesn't log individual row deletions

• Truncate resets auto-increment values while delete doesn't

• Truncate can't be undone while delete can be rolled back

• Truncate doesn't trigger any triggers while delete does

Abstract class can have both abstract and non-abstract methods, while interface can only have abstract methods.

• Abstract class can have constructors, fields, and non-abstract methods, while interface cannot.

• A class can implement multiple interfaces but can only inherit from one abstract class.

• Abstract classes are used to define a common behavior for subclasses, while interfaces are used to define a contract for classes to implement.

• Example: Abstract class 'Animal' with abstrac...read more

Redux is a predictable state container for JavaScript apps. It helps manage the state of an application in a more organized and efficient way.

• Redux is used in React applications to manage the state of the application.

• It helps in maintaining a single source of truth for the state.

• Redux allows for easier debugging and testing of the application.

• Actions are dispatched to update the state in a predictable way.

• Selectors can be used to retrieve specific pieces of state from the sto...read more

Unit testing is a software testing technique where individual units or components of a software are tested in isolation.

• Unit testing helps in identifying bugs early in the development process.

• It ensures that each unit of the software performs as expected.

• Common unit testing tools include JUnit, NUnit, PHPUnit, and MSTest.

I handle difficult clients by remaining calm, listening actively, and finding solutions to their concerns.

• Remain calm and composed during interactions

• Listen actively to understand their concerns and frustrations

• Empathize with their perspective and show understanding

• Find solutions to address their issues and communicate effectively

Code using hashmap and HashSet

• Create a HashMap object

• Add key-value pairs to the HashMap

• Create a HashSet object

• Add elements to the HashSet

• Retrieve values from the HashMap using keys in the HashSet

Software developers need to have strong technical skills, problem-solving abilities, and communication skills.

• Strong technical skills in programming languages, databases, and software development tools

• Problem-solving abilities to identify and solve complex software issues

• Communication skills to work effectively with team members and clients

• Adaptability to learn new technologies and keep up with industry trends

• Creativity to develop innovative solutions to software problems

• Atte...read more

Object is a fundamental concept in Python, representing a data structure that has properties and methods.

• Objects are instances of classes

• Objects have attributes and methods

• Objects can be created using constructors

• Objects can be passed as arguments to functions

• Objects can be used to implement object-oriented programming

• Examples of objects include lists, dictionaries, and strings

Logical thinking in programming involves the ability to break down complex problems into smaller, manageable parts and to create a step-by-step plan to solve them.

• Identifying patterns and relationships between different elements in the problem

• Breaking down the problem into smaller subproblems

• Creating a logical sequence of steps to solve each subproblem

• Using conditional statements and loops to control the flow of the program

• Testing and debugging the code to ensure it functions...read more

Program to check if a number is prime or not.

• A prime number is only divisible by 1 and itself.

• Loop through numbers from 2 to n-1 and check if n is divisible by any of them.

• If n is divisible by any number, it is not prime.

• If n is not divisible by any number, it is prime.

Java is independent because of its platform-independent nature.

• Java code is compiled into bytecode which can run on any platform with a JVM installed.

• This allows Java to be used on multiple operating systems without any changes to the code.

• Java's platform independence is achieved through the use of the Java Virtual Machine (JVM).

COBOL has four divisions: Identification, Environment, Data, and Procedure.

• Identification Division: contains program name and author information

• Environment Division: contains configuration information for the program

• Data Division: contains data definitions used in the program

• Procedure Division: contains the actual program logic and instructions

Entity Framework is an ORM (Object-Relational Mapping) framework in .NET for interacting with databases.

• Simplifies database interactions by allowing developers to work with database objects as .NET objects

• Automatically generates SQL queries based on LINQ queries

• Handles database operations like insert, update, delete, and retrieval of data

Inheritance is a mechanism in object-oriented programming where a class inherits properties and behaviors from another class.

• Inheritance allows a class to reuse code from another class, promoting code reusability and reducing redundancy.

• The class that is being inherited from is called the parent class or base class, while the class that inherits from it is called the child class or derived class.

• Child classes can access and modify the properties and methods of the parent clas...read more

Python is a high-level, interpreted programming language. Java is a general-purpose, class-based, object-oriented programming language.

• Python was created by Guido van Rossum in the late 1980s and released in 1991.

• Java was developed by James Gosling and his team at Sun Microsystems in the mid-1990s.

• Python is known for its simplicity, readability, and ease of use.

• Java is known for its platform independence, security, and scalability.

• Python is widely used in web development, sci...read more

Filter is a method used to select elements from a collection based on a certain condition.

• Filter function returns a new array with elements that pass a certain condition

• Example: filtering even numbers from an array [1, 2, 3, 4, 5] would result in [2, 4]

Software requirements are the functional and non-functional specifications that a software system must meet.

• Software requirements define what the software should do and how it should behave

• They include functional requirements (what the software should do) and non-functional requirements (how well it should do it)

• Requirements are typically documented in a requirements specification document

• They are used to guide the development process and ensure that the software meets the ne...read more

Software technology refers to the tools, languages, frameworks, and methodologies used to develop software applications.

• Software technology includes programming languages such as Java, Python, and C++

• Frameworks like React, Angular, and Vue.js are used for building web applications

• Methodologies like Agile and Waterfall are used for project management

• Tools like Git, JIRA, and Jenkins are used for version control, issue tracking, and continuous integration

• Software technology is ...read more

Data can be passed to COBOL using input/output files, parameters, or through communication with other programs.

• Data can be passed to COBOL programs through input/output files. The program reads data from input files and writes output to output files.

• Parameters can be used to pass data to COBOL programs. Data can be passed as arguments when calling the program.

• COBOL programs can communicate with other programs using communication methods like sockets or APIs to exchange data.

Bundling and minification are techniques used in web development to optimize the performance of a website by reducing the size of files.

• Bundling involves combining multiple files into a single file to reduce the number of HTTP requests needed to load a webpage.

• Minification is the process of removing unnecessary characters from code without affecting its functionality, such as white spaces, comments, and line breaks.

• Both bundling and minification help improve website loading t...read more

Longest substring refers to finding the continuous sequence of characters within a string with no repeating characters.

• Iterate through the string and keep track of the characters seen so far

• Use a hashmap to store the index of each character

• Update the start index of the substring when a repeating character is encountered

• Calculate the length of the current substring and update the longest substring found so far

JS stands for JavaScript, a programming language commonly used for web development. Async JS refers to asynchronous JavaScript, which allows for non-blocking code execution.

• JS is a programming language used for web development.

• Async JS allows for non-blocking code execution.

• Async JS is commonly used for tasks like fetching data from a server without blocking the rest of the code execution.

Design Patterns are reusable solutions to commonly occurring problems in software design.

• Design Patterns provide a common vocabulary for developers to communicate about solutions to problems.

• They help in making code more flexible, reusable, and maintainable.

• Examples of Design Patterns include Singleton, Factory, Observer, and Decorator.

DS stands for Data Structures. There are various types of DS used in programming.

• Arrays

• Linked Lists

• Stacks

• Queues

• Trees

• Graphs

• Hash Tables

• Heaps

DSA based programming refers to using data structures and algorithms in programming to solve complex problems efficiently.

• DSA stands for Data Structures and Algorithms

• It involves implementing various data structures like arrays, linked lists, trees, graphs, etc.

• It also involves using algorithms like sorting, searching, dynamic programming, etc.

• DSA based programming helps in writing efficient and optimized code

• Example: Implementing a sorting algorithm like quicksort to sort an...read more

COBOL (Common Business-Oriented Language) is a high-level programming language used primarily for business, finance, and administrative systems on mainframe computers.

• COBOL is one of the oldest programming languages, designed in the late 1950s.

• It is known for its readability and self-documenting code.

• COBOL is still widely used in legacy systems, especially in the financial and government sectors.

• Example: COBOL programs are often used for processing large volumes of data in ba...read more

Exception handling is a mechanism to handle runtime errors in a program to prevent it from crashing.

• It allows the program to gracefully handle unexpected situations.

• Exceptions can be caught and handled using try-catch blocks.

• Common exceptions include NullPointerException, ArrayIndexOutOfBoundsException, and IOException.

• Handling exceptions properly can improve the reliability and robustness of a software application.

Software is developed to solve problems and automate tasks.

• To improve efficiency and productivity

• To provide solutions to complex problems

• To automate repetitive tasks

• To enhance user experience

• To enable communication and collaboration

• To store and manage data

• To provide entertainment and leisure activities

A software system is a collection of programs, data, and documentation that work together to perform a specific task.

• A software system is designed to solve a particular problem or set of problems.

• It consists of various components such as databases, user interfaces, and application servers.

• Examples of software systems include operating systems, web browsers, and mobile apps.

An object in OOPS is an instance of a class that encapsulates data and behavior.

• Objects have attributes (data) and methods (behavior)

• Objects are created from classes

• Objects can interact with each other through method calls

• Example: A 'Car' class can have objects like 'Toyota', 'Honda', etc.

Quadruple sign is a term used in software development to refer to four consecutive characters in a string.

• Quadruple sign is used to describe four characters in a row within a string.

• It can be used to check for specific patterns or sequences in a text.

• For example, 'abcd' is a quadruple sign in the string 'abcde'.

Quantum Computing - the latest technology from the field of computer science.

• Quantum computing uses quantum bits (qubits) instead of classical bits for faster computation.

• It has the potential to solve complex problems that classical computers cannot.

• Companies like IBM, Google, and Microsoft are investing heavily in quantum computing research.

• Quantum computing is still in its early stages and has a long way to go before it becomes mainstream.

A marker interface is an interface with no methods, used to mark classes for special treatment.

• Marker interfaces do not have any methods to implement.

• They are used to add metadata to classes at runtime.

• Examples include Serializable interface in Java.

• Marker interfaces are often used for type checking or to enable special behavior.

Binary search is a search algorithm that finds the position of a target value within a sorted array.

• Divide the array in half and compare the target value with the middle element

• If the target value is smaller, search the left half. If larger, search the right half

• Repeat the process until the target value is found or the subarray is empty

Generics in C# allow you to create classes, interfaces, and methods that operate on data types without specifying the actual data type until it is used.

• Generics provide type safety, reusability, and performance improvements.

• Example: List allows you to create a list of any data type.

• Example: Dictionary allows you to create a dictionary with keys and values of any data type.

Stack is a data structure that follows Last In First Out (LIFO) principle. Queue is a data structure that follows First In First Out (FIFO) principle.

• Stack: Last In First Out (LIFO) data structure. Example: stack of plates.

• Queue: First In First Out (FIFO) data structure. Example: waiting line at a ticket counter.

A Burn Down Chart is a visual representation of work remaining versus time in a sprint or project.

• It helps track the progress of a project by showing the amount of work completed over time.

• The chart typically has a horizontal axis representing time and a vertical axis representing work remaining.

• The ideal trend line shows work decreasing over time, with the goal of completing all work by the end of the project.

• It is commonly used in Agile and Scrum methodologies to monitor an...read more

My dream is to create a platform that connects people with mental health professionals easily and affordably.

• Develop a user-friendly interface for clients to search and book appointments with therapists

• Implement a secure payment system for transactions

• Partner with licensed therapists to provide quality care

• Incorporate teletherapy options for remote sessions

• Offer personalized recommendations based on client needs and preferences

Angular is a popular front-end framework for building dynamic web applications.

• Developed and maintained by Google

• Uses TypeScript for building applications

• Follows the MVC (Model-View-Controller) architecture

• Supports two-way data binding

• Has a powerful CLI for scaffolding projects

Side effects are unintended consequences of a software function that can impact other parts of the system.

• Side effects can include changing the state of variables outside the function's scope

• They can also involve modifying global variables or causing unexpected behavior in other functions

• Examples of side effects include printing to the console, modifying a database, or updating a user interface

WSDL document describes web services and their functionalities.

• WSDL stands for Web Services Description Language

• It is an XML document that describes web services and their functionalities

• WSDL defines the operations, input and output parameters, and data types used by a web service

• It allows clients to understand how to interact with a web service

Multithreading is the ability of a CPU to execute multiple threads concurrently.

• Multithreading allows for parallel execution of tasks on a single CPU core.

• Each thread has its own program counter, stack, and set of registers.

• Example: A web server handling multiple client requests simultaneously using multithreading.

• Example: A video game rendering graphics while processing user input using multithreading.

Create a CRUD app in Angular within 15 minutes

• Set up Angular project with CLI

• Create components for Create, Read, Update, and Delete operations

• Implement services to interact with backend API

• Use Angular Material for UI components

• Test the app functionality

A data structure that stores a sequence of elements in which each element points to the next one.

• Consists of nodes that contain data and a pointer to the next node

• Can be singly linked or doubly linked

• Used for dynamic memory allocation, implementing stacks, queues, and hash tables

Java is a high-level, object-oriented programming language used to develop applications for various platforms.

• Java is platform-independent and can run on any device with a Java Virtual Machine (JVM)

• It was developed by James Gosling at Sun Microsystems (now owned by Oracle)

• Java is used for developing web applications, mobile applications, desktop applications, and games

• It is known for its security features and automatic memory management

• Java code is compiled into bytecode, whi...read more

Inheritance is a mechanism in object-oriented programming where a new class is created by inheriting properties of an existing class.

• Inheritance allows code reuse and promotes code organization.

• The existing class is called the parent or superclass, and the new class is called the child or subclass.

• The child class inherits all the properties and methods of the parent class and can also add its own unique properties and methods.

• For example, a class Animal can be a parent class,...read more

Annotations are used in Spring Boot to simplify the configuration and development of applications.

• Annotations like @Controller, @RestController, @Service, @Repository are used to define components

• Annotations like @RequestMapping, @GetMapping, @PostMapping are used to define request mappings

• Annotations like @Autowired, @Qualifier are used for dependency injection

Promises and async are used in Node.js for asynchronous programming.

• Promises are objects that represent the eventual completion or failure of an asynchronous operation.

• Async/await is a way to write asynchronous code that looks like synchronous code.

• Node.js uses an event-driven, non-blocking I/O model that makes it well-suited for asynchronous programming.

• Example: Using promises to fetch data from an API and handle the response.

• Example: Using async/await to read a file and log...read more

Abstraction is hiding the implementation details while interface is a contract that defines the methods that a class must implement.

• Abstraction is achieved through abstract classes or interfaces in object-oriented programming.

• Abstraction allows us to hide complex implementation details and only show the necessary features to the outside world.

• Interfaces in Java are used to define a contract that a class must follow by implementing all the methods declared in the interface.

• Abs...read more

Encapsulation is the concept of bundling data and methods that operate on the data into a single unit.

• Encapsulation helps in hiding the internal state of an object and restricting access to it.

• It allows for better control over the data by preventing direct access from outside the class.

• Encapsulation also helps in achieving data abstraction and information hiding.

• Example: In a class representing a car, the variables like speed and fuel level can be encapsulated along with meth...read more

DSA stands for Data Structures and Algorithms, which are fundamental concepts in computer science for solving complex problems efficiently.

• DSA involves organizing and storing data in a way that allows for efficient retrieval and manipulation.

• Algorithms are step-by-step procedures for solving problems, while data structures are ways to store and organize data.

• Examples of DSA questions include sorting algorithms like quicksort or data structures like linked lists.

HTML stands for Hypertext Markup Language, used for creating and structuring web pages.

• HTML is a markup language used to create the structure of web pages

• It consists of elements enclosed in tags, such as <html>, <head>, <body>

• Attributes can be added to elements to provide additional information or functionality, like <img src='image.jpg'>

The question is unclear and lacks context.

• Please provide more information or context for me to answer the question.

• Without additional information, I cannot provide a meaningful answer.

Triggers are database objects that are automatically executed in response to specified events.

• Triggers are used to enforce business rules, maintain data integrity, and automate tasks.

• They can be defined to execute before or after an INSERT, UPDATE, or DELETE operation.

• Triggers can be written in SQL or procedural languages like PL/SQL or T-SQL.

• Examples of triggers include auditing changes to a table, updating denormalized data, or sending notifications.

Types of streams in Node.js include Readable, Writable, Duplex, and Transform streams.

• Readable streams allow reading data from a source.

• Writable streams allow writing data to a destination.

• Duplex streams allow both reading and writing.

• Transform streams modify data as it is being read or written.

• Example: fs.createReadStream() creates a Readable stream for reading a file.

REST API is a type of web service that allows communication between different systems over HTTP using standard methods like GET, POST, PUT, DELETE.

• REST stands for Representational State Transfer

• Uses standard HTTP methods like GET, POST, PUT, DELETE for communication

• Data is transferred in JSON or XML format

• Stateless communication between client and server

• Example: GET request to retrieve user data from a server

A hashtable is a data structure that stores key-value pairs and allows for quick retrieval of values based on their keys.

• Uses a hash function to map keys to indexes in an array

• Provides constant time complexity for insertion, deletion, and retrieval operations

• Commonly used in programming languages like Java and Python for implementing dictionaries or maps

Streams are used for processing elements from a data source sequentially, while collections are used for storing and managing groups of objects.

• Streams are lazy and can be processed in parallel, while collections are eager and store all elements in memory.

• Streams support functional-style operations like map, filter, and reduce, while collections provide methods like add, remove, and contains.

• Example: List names = Arrays.asList("Alice", "Bob", "Charlie"); Stream stream = names...read more