Web Development Interview Questions for Freshers
1. What happens when you type a URL in your browser and press Enter?
Answer:
DNS lookup happens to find the IP address
Browser sends an HTTP/HTTPS request to the server
Server processes and sends back HTML/CSS/JS
Browser renders the page using its rendering engine
2. What is the difference between GET and POST requests?
Answer:
GET: Sends data in the URL, used for fetching data
POST: Sends data in the body, used for submitting data securely
3. What is a responsive website?
Answer:
A responsive website adjusts layout and design based on screen size and device (mobile, tablet, desktop), usually using CSS media queries.
4. What is the role of Webpack in web development?
Answer:
Webpack bundles JavaScript files, CSS, and assets into optimized output for faster website loading and better performance.
5. What is the purpose of async and defer in script tags?
Answer:
async: Loads script asynchronously and executes it immediately
defer: Loads script asynchronously but executes after HTML is parsed
6. What is the difference between localStorage and sessionStorage?
Answer:
localStorage: Stores data with no expiration
sessionStorage: Stores data until the browser tab is closed
7. What is CORS?
Answer:
CORS (Cross-Origin Resource Sharing) is a browser security feature that restricts cross-domain API calls unless the server allows it.
8. What is the difference between null and undefined in JavaScript?
Answer:
undefined: A variable declared but not assigned a value
null: A variable explicitly set to have no value
9. How do you optimize website performance?
Answer:
Minify CSS/JS
Compress images
Use lazy loading
Use caching
Reduce HTTP requests
Use a CDN
10. What is the DOM?
Answer:
DOM (Document Object Model) represents the structure of an HTML document as objects, which JavaScript can interact with to change content dynamically.
Credits: https://whatsapp.com/channel/0029VaiSdWu4NVis9yNEE72z/847
1. What happens when you type a URL in your browser and press Enter?
Answer:
DNS lookup happens to find the IP address
Browser sends an HTTP/HTTPS request to the server
Server processes and sends back HTML/CSS/JS
Browser renders the page using its rendering engine
2. What is the difference between GET and POST requests?
Answer:
GET: Sends data in the URL, used for fetching data
POST: Sends data in the body, used for submitting data securely
3. What is a responsive website?
Answer:
A responsive website adjusts layout and design based on screen size and device (mobile, tablet, desktop), usually using CSS media queries.
4. What is the role of Webpack in web development?
Answer:
Webpack bundles JavaScript files, CSS, and assets into optimized output for faster website loading and better performance.
5. What is the purpose of async and defer in script tags?
Answer:
async: Loads script asynchronously and executes it immediately
defer: Loads script asynchronously but executes after HTML is parsed
6. What is the difference between localStorage and sessionStorage?
Answer:
localStorage: Stores data with no expiration
sessionStorage: Stores data until the browser tab is closed
7. What is CORS?
Answer:
CORS (Cross-Origin Resource Sharing) is a browser security feature that restricts cross-domain API calls unless the server allows it.
8. What is the difference between null and undefined in JavaScript?
Answer:
undefined: A variable declared but not assigned a value
null: A variable explicitly set to have no value
9. How do you optimize website performance?
Answer:
Minify CSS/JS
Compress images
Use lazy loading
Use caching
Reduce HTTP requests
Use a CDN
10. What is the DOM?
Answer:
DOM (Document Object Model) represents the structure of an HTML document as objects, which JavaScript can interact with to change content dynamically.
Credits: https://whatsapp.com/channel/0029VaiSdWu4NVis9yNEE72z/847
โค1
Web Development Interview Questions Part-2
11. What are semantic HTML elements?
Answer:
Semantic elements clearly describe their meaning in a human- and machine-readable way. Examples: <header>, <footer>, <article>, <nav>.
12. What are HTTP status codes?
Answer:
They indicate the result of an HTTP request.
Common ones:
200 OK (Success)
404 Not Found
500 Internal Server Error
401 Unauthorized
403 Forbidden
13. What is the box model in CSS?
Answer:
The box model includes:
Content
Padding
Border
Margin
It defines how space is taken up around HTML elements.
14. What are pseudo-classes in CSS?
Answer:
Pseudo-classes style elements based on their state.
Examples:
:hover (when mouse is over)
:first-child
:nth-child()
15. How do you make a website SEO-friendly?
Answer:
Use semantic HTML
Add meta tags and alt text
Mobile responsiveness
Fast loading speed
Proper URL structure
16. What is the difference between synchronous and asynchronous in JavaScript?
Answer:
Synchronous: Code runs line by line
Asynchronous: Tasks like API calls don't block other code; use callbacks, promises, or async/await
17. What is a promise in JavaScript?
Answer:
A Promise represents the result of an async operation.
It can be:
Pending
Fulfilled
Rejected
18. What is event bubbling and capturing in JavaScript?
Answer:
Bubbling: Event propagates from child to parent
Capturing: Event goes from parent to child
You can control it using event.stopPropagation()
19. What is a CDN?
Answer:
CDN (Content Delivery Network) delivers static files (images, CSS, JS) via servers closest to the user to improve website speed.
20. What tools do you use for version control?
Answer:
Most common: Git + GitHub
Git tracks changes in code, and GitHub helps you collaborate and manage versions.
Credits: https://whatsapp.com/channel/0029VaiSdWu4NVis9yNEE72z/847
11. What are semantic HTML elements?
Answer:
Semantic elements clearly describe their meaning in a human- and machine-readable way. Examples: <header>, <footer>, <article>, <nav>.
12. What are HTTP status codes?
Answer:
They indicate the result of an HTTP request.
Common ones:
200 OK (Success)
404 Not Found
500 Internal Server Error
401 Unauthorized
403 Forbidden
13. What is the box model in CSS?
Answer:
The box model includes:
Content
Padding
Border
Margin
It defines how space is taken up around HTML elements.
14. What are pseudo-classes in CSS?
Answer:
Pseudo-classes style elements based on their state.
Examples:
:hover (when mouse is over)
:first-child
:nth-child()
15. How do you make a website SEO-friendly?
Answer:
Use semantic HTML
Add meta tags and alt text
Mobile responsiveness
Fast loading speed
Proper URL structure
16. What is the difference between synchronous and asynchronous in JavaScript?
Answer:
Synchronous: Code runs line by line
Asynchronous: Tasks like API calls don't block other code; use callbacks, promises, or async/await
17. What is a promise in JavaScript?
Answer:
A Promise represents the result of an async operation.
It can be:
Pending
Fulfilled
Rejected
18. What is event bubbling and capturing in JavaScript?
Answer:
Bubbling: Event propagates from child to parent
Capturing: Event goes from parent to child
You can control it using event.stopPropagation()
19. What is a CDN?
Answer:
CDN (Content Delivery Network) delivers static files (images, CSS, JS) via servers closest to the user to improve website speed.
20. What tools do you use for version control?
Answer:
Most common: Git + GitHub
Git tracks changes in code, and GitHub helps you collaborate and manage versions.
Credits: https://whatsapp.com/channel/0029VaiSdWu4NVis9yNEE72z/847
โค5
Complete JavaScript Road Map๐ฅ
A-Z JavaScript๐
1.Variables
โณ var
โณ let
โณ const
2. Data Types
โณ number
โณ string
โณ boolean
โณ null
โณ undefined
โณ symbol
3.Declaring variables
โณ var
โณ let
โณ const
4.Expressions
Primary expressions
โณ this
โณ Literals
โณ []
โณ {}
โณ function
โณ class
โณ function*
โณ async function
โณ async function*
โณ /ab+c/i
โณ
โณ ( )
Left-hand-side expressions
โณ Property accessors
โณ ?.
โณ new
โณ new .target
โณ import.iss.oneta
โณ super
โณ import()
5.operators
โณ Arithmetic Operators: +, -, *, /, %
โณ Comparison Operators: ==, ===, !=, !==, <, >, <=, >=
โณ Logical Operators: &&, ||, !
6.Control Structures
โณ if
โณ else if
โณ else
โณ switch
โณ case
โณ default
7.Iterations/Loop
โณ do...while
โณ for
โณ for...in
โณ for...of
โณ for await...of
โณ while
8.Functions
โณ Arrow Functions
โณ Default parameters
โณ Rest parameters
โณ arguments
โณ Method definitions
โณ getter
โณ setter
9.Objects and Arrays
โณ Object Literal: { key: value }
โณ Array Literal: [element1, element2, ...]
โณ Object Methods and Properties
โณ Array Methods: push(), pop(), shift(), unshift(),
splice(), slice(), forEach(), map(), filter()
10.Classes and Prototypes
โณ Class Declaration
โณ Constructor Functions
โณ Prototypal Inheritance
โณ extends keyword
โณ super keyword
โณ Private class features
โณ Public class fields
โณ static
โณ Static initialization blocks
11.Error Handling
โณ try,
โณ catch,
โณ finally (exception handling)
ADVANCED CONCEPTS
--------------------------
12.Closures
โณ Lexical Scope
โณ Function Scope
โณ Closure Use Cases
13.Asynchronous JavaScript
โณ Callback Functions
โณ Promises
โณ async/await Syntax
โณ Fetch API
โณ XMLHttpRequest
14.Modules
โณ import and export Statements (ES6 Modules)
โณ CommonJS Modules (require, module.exports)
15.Event Handling
โณ Event Listeners
โณ Event Object
โณ Bubbling and Capturing
16.DOM Manipulation
โณ Selecting DOM Elements
โณ Modifying Element Properties
โณ Creating and Appending Elements
17.Regular Expressions
โณ Pattern Matching
โณ RegExp Methods: test(), exec(), match(), replace()
18.Browser APIs
โณ localStorage and sessionStorage
โณ navigator Object
โณ Geolocation API
โณ Canvas API
19.Web APIs
โณ setTimeout(), setInterval()
โณ XMLHttpRequest
โณ Fetch API
โณ WebSockets
20.Functional Programming
โณ Higher-Order Functions
โณ map(), reduce(), filter()
โณ Pure Functions and Immutability
21.Promises and Asynchronous Patterns
โณ Promise Chaining
โณ Error Handling with Promises
โณ Async/Await
22.ES6+ Features
โณ Template Literals
โณ Destructuring Assignment
โณ Rest and Spread Operators
โณ Arrow Functions
โณ Classes and Inheritance
โณ Default Parameters
โณ let, const Block Scoping
23.Browser Object Model (BOM)
โณ window Object
โณ history Object
โณ location Object
โณ navigator Object
24.Node.js Specific Concepts
โณ require()
โณ Node.js Modules (module.exports)
โณ File System Module (fs)
โณ npm (Node Package Manager)
25.Testing Frameworks
โณ Jasmine
โณ Mocha
โณ Jest
------------------- END-------------------
Some Good Resources To Learn JavaScript
1.Documentation
Mozilla MDN Web Docs
developer.mozilla.org/en-US/docs/Webโฆ
DevDocs
devdocs.io/javascript/
2. Useful Channel's
Javascript Courses: https://t.iss.one/javascript_courses
Programming Resources: https://t.iss.one/programming_guide
FreeCodeCamp: youtube.com/c/FreeCodeCamp
Hope it helps ๐๐ฑ
A-Z JavaScript๐
1.Variables
โณ var
โณ let
โณ const
2. Data Types
โณ number
โณ string
โณ boolean
โณ null
โณ undefined
โณ symbol
3.Declaring variables
โณ var
โณ let
โณ const
4.Expressions
Primary expressions
โณ this
โณ Literals
โณ []
โณ {}
โณ function
โณ class
โณ function*
โณ async function
โณ async function*
โณ /ab+c/i
โณ
string
โณ ( )
Left-hand-side expressions
โณ Property accessors
โณ ?.
โณ new
โณ new .target
โณ import.iss.oneta
โณ super
โณ import()
5.operators
โณ Arithmetic Operators: +, -, *, /, %
โณ Comparison Operators: ==, ===, !=, !==, <, >, <=, >=
โณ Logical Operators: &&, ||, !
6.Control Structures
โณ if
โณ else if
โณ else
โณ switch
โณ case
โณ default
7.Iterations/Loop
โณ do...while
โณ for
โณ for...in
โณ for...of
โณ for await...of
โณ while
8.Functions
โณ Arrow Functions
โณ Default parameters
โณ Rest parameters
โณ arguments
โณ Method definitions
โณ getter
โณ setter
9.Objects and Arrays
โณ Object Literal: { key: value }
โณ Array Literal: [element1, element2, ...]
โณ Object Methods and Properties
โณ Array Methods: push(), pop(), shift(), unshift(),
splice(), slice(), forEach(), map(), filter()
10.Classes and Prototypes
โณ Class Declaration
โณ Constructor Functions
โณ Prototypal Inheritance
โณ extends keyword
โณ super keyword
โณ Private class features
โณ Public class fields
โณ static
โณ Static initialization blocks
11.Error Handling
โณ try,
โณ catch,
โณ finally (exception handling)
ADVANCED CONCEPTS
--------------------------
12.Closures
โณ Lexical Scope
โณ Function Scope
โณ Closure Use Cases
13.Asynchronous JavaScript
โณ Callback Functions
โณ Promises
โณ async/await Syntax
โณ Fetch API
โณ XMLHttpRequest
14.Modules
โณ import and export Statements (ES6 Modules)
โณ CommonJS Modules (require, module.exports)
15.Event Handling
โณ Event Listeners
โณ Event Object
โณ Bubbling and Capturing
16.DOM Manipulation
โณ Selecting DOM Elements
โณ Modifying Element Properties
โณ Creating and Appending Elements
17.Regular Expressions
โณ Pattern Matching
โณ RegExp Methods: test(), exec(), match(), replace()
18.Browser APIs
โณ localStorage and sessionStorage
โณ navigator Object
โณ Geolocation API
โณ Canvas API
19.Web APIs
โณ setTimeout(), setInterval()
โณ XMLHttpRequest
โณ Fetch API
โณ WebSockets
20.Functional Programming
โณ Higher-Order Functions
โณ map(), reduce(), filter()
โณ Pure Functions and Immutability
21.Promises and Asynchronous Patterns
โณ Promise Chaining
โณ Error Handling with Promises
โณ Async/Await
22.ES6+ Features
โณ Template Literals
โณ Destructuring Assignment
โณ Rest and Spread Operators
โณ Arrow Functions
โณ Classes and Inheritance
โณ Default Parameters
โณ let, const Block Scoping
23.Browser Object Model (BOM)
โณ window Object
โณ history Object
โณ location Object
โณ navigator Object
24.Node.js Specific Concepts
โณ require()
โณ Node.js Modules (module.exports)
โณ File System Module (fs)
โณ npm (Node Package Manager)
25.Testing Frameworks
โณ Jasmine
โณ Mocha
โณ Jest
------------------- END-------------------
Some Good Resources To Learn JavaScript
1.Documentation
Mozilla MDN Web Docs
developer.mozilla.org/en-US/docs/Webโฆ
DevDocs
devdocs.io/javascript/
2. Useful Channel's
Javascript Courses: https://t.iss.one/javascript_courses
Programming Resources: https://t.iss.one/programming_guide
FreeCodeCamp: youtube.com/c/FreeCodeCamp
Hope it helps ๐๐ฑ
โค3
๐ ๐๐ฒ๐ญ๐ก๐จ๐ง ๐๐๐ฅ๐ญ ๐ข๐ฆ๐ฉ๐จ๐ฌ๐ฌ๐ข๐๐ฅ๐ ๐๐ญ ๐๐ข๐ซ๐ฌ๐ญ, ๐๐ฎ๐ญ ๐ญ๐ก๐๐ฌ๐ ๐ ๐ฌ๐ญ๐๐ฉ๐ฌ ๐๐ก๐๐ง๐ ๐๐ ๐๐ฏ๐๐ซ๐ฒ๐ญ๐ก๐ข๐ง๐ !
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1๏ธโฃ ๐๐๐ฌ๐ญ๐๐ซ๐๐ ๐ญ๐ก๐ ๐๐๐ฌ๐ข๐๐ฌ: Started with foundational Python concepts like variables, loops, functions, and conditional statements.
2๏ธโฃ ๐๐ซ๐๐๐ญ๐ข๐๐๐ ๐๐๐ฌ๐ฒ ๐๐ซ๐จ๐๐ฅ๐๐ฆ๐ฌ: Focused on beginner-friendly problems on platforms like LeetCode and HackerRank to build confidence.
3๏ธโฃ ๐ ๐จ๐ฅ๐ฅ๐จ๐ฐ๐๐ ๐๐ฒ๐ญ๐ก๐จ๐ง-๐๐ฉ๐๐๐ข๐๐ข๐ ๐๐๐ญ๐ญ๐๐ซ๐ง๐ฌ: Studied essential problem-solving techniques for Python, like list comprehensions, dictionary manipulations, and lambda functions.
4๏ธโฃ ๐๐๐๐ซ๐ง๐๐ ๐๐๐ฒ ๐๐ข๐๐ซ๐๐ซ๐ข๐๐ฌ: Explored popular libraries like Pandas, NumPy, and Matplotlib for data manipulation, analysis, and visualization.
5๏ธโฃ ๐ ๐จ๐๐ฎ๐ฌ๐๐ ๐จ๐ง ๐๐ซ๐จ๐ฃ๐๐๐ญ๐ฌ: Built small projects like a to-do app, calculator, or data visualization dashboard to apply concepts.
6๏ธโฃ ๐๐๐ญ๐๐ก๐๐ ๐๐ฎ๐ญ๐จ๐ซ๐ข๐๐ฅ๐ฌ: Followed creators like CodeWithHarry and Shradha Khapra for in-depth Python tutorials.
7๏ธโฃ ๐๐๐๐ฎ๐ ๐ ๐๐ ๐๐๐ ๐ฎ๐ฅ๐๐ซ๐ฅ๐ฒ: Made it a habit to debug and analyze code to understand errors and optimize solutions.
8๏ธโฃ ๐๐จ๐ข๐ง๐๐ ๐๐จ๐๐ค ๐๐จ๐๐ข๐ง๐ ๐๐ก๐๐ฅ๐ฅ๐๐ง๐ ๐๐ฌ: Participated in coding challenges to simulate real-world problem-solving scenarios.
9๏ธโฃ ๐๐ญ๐๐ฒ๐๐ ๐๐จ๐ง๐ฌ๐ข๐ฌ๐ญ๐๐ง๐ญ: Practiced daily, worked on diverse problems, and never skipped Python for more than a day.
I have curated the best interview resources to crack Python Interviews ๐๐
https://whatsapp.com/channel/0029VaiM08SDuMRaGKd9Wv0L
Hope you'll like it
Like this post if you need more resources like this ๐โค๏ธ
#Python
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1๏ธโฃ ๐๐๐ฌ๐ญ๐๐ซ๐๐ ๐ญ๐ก๐ ๐๐๐ฌ๐ข๐๐ฌ: Started with foundational Python concepts like variables, loops, functions, and conditional statements.
2๏ธโฃ ๐๐ซ๐๐๐ญ๐ข๐๐๐ ๐๐๐ฌ๐ฒ ๐๐ซ๐จ๐๐ฅ๐๐ฆ๐ฌ: Focused on beginner-friendly problems on platforms like LeetCode and HackerRank to build confidence.
3๏ธโฃ ๐ ๐จ๐ฅ๐ฅ๐จ๐ฐ๐๐ ๐๐ฒ๐ญ๐ก๐จ๐ง-๐๐ฉ๐๐๐ข๐๐ข๐ ๐๐๐ญ๐ญ๐๐ซ๐ง๐ฌ: Studied essential problem-solving techniques for Python, like list comprehensions, dictionary manipulations, and lambda functions.
4๏ธโฃ ๐๐๐๐ซ๐ง๐๐ ๐๐๐ฒ ๐๐ข๐๐ซ๐๐ซ๐ข๐๐ฌ: Explored popular libraries like Pandas, NumPy, and Matplotlib for data manipulation, analysis, and visualization.
5๏ธโฃ ๐ ๐จ๐๐ฎ๐ฌ๐๐ ๐จ๐ง ๐๐ซ๐จ๐ฃ๐๐๐ญ๐ฌ: Built small projects like a to-do app, calculator, or data visualization dashboard to apply concepts.
6๏ธโฃ ๐๐๐ญ๐๐ก๐๐ ๐๐ฎ๐ญ๐จ๐ซ๐ข๐๐ฅ๐ฌ: Followed creators like CodeWithHarry and Shradha Khapra for in-depth Python tutorials.
7๏ธโฃ ๐๐๐๐ฎ๐ ๐ ๐๐ ๐๐๐ ๐ฎ๐ฅ๐๐ซ๐ฅ๐ฒ: Made it a habit to debug and analyze code to understand errors and optimize solutions.
8๏ธโฃ ๐๐จ๐ข๐ง๐๐ ๐๐จ๐๐ค ๐๐จ๐๐ข๐ง๐ ๐๐ก๐๐ฅ๐ฅ๐๐ง๐ ๐๐ฌ: Participated in coding challenges to simulate real-world problem-solving scenarios.
9๏ธโฃ ๐๐ญ๐๐ฒ๐๐ ๐๐จ๐ง๐ฌ๐ข๐ฌ๐ญ๐๐ง๐ญ: Practiced daily, worked on diverse problems, and never skipped Python for more than a day.
I have curated the best interview resources to crack Python Interviews ๐๐
https://whatsapp.com/channel/0029VaiM08SDuMRaGKd9Wv0L
Hope you'll like it
Like this post if you need more resources like this ๐โค๏ธ
#Python
โค3
Top Libraries & Frameworks by Language ๐๐ป
โฏ Python
โโข Pandas โ Data Analysis
โโข NumPy โ Math & Arrays
โโข Scikit-learn โ Machine Learning
โโข TensorFlow / PyTorch โ Deep Learning
โโข Flask / Django โ Web Development
โโข OpenCV โ Image Processing
โฏ JavaScript / TypeScript
โโข React โ UI Development
โโข Vue โ Lightweight SPAs
โโข Angular โ Enterprise Apps
โโข Next.js โ Full-Stack Web
โโข Express โ Backend APIs
โโข Three.js โ 3D Web Graphics
โฏ Java
โโข Spring Boot โ Microservices
โโข Hibernate โ ORM
โโข Apache Maven โ Build Automation
โโข Apache Kafka โ Real-Time Data
โฏ C++
โโข Boost โ Utility Libraries
โโข Qt โ GUI Applications
โโข Unreal Engine โ Game Development
โฏ C#
โโข .NET / ASP.NET โ Web Apps
โโข Unity โ Game Development
โโข Entity Framework โ ORM
โฏ R
โโข ggplot2 โ Data Visualization
โโข dplyr โ Data Manipulation
โโข caret โ Machine Learning
โโข Shiny โ Interactive Dashboards
โฏ PHP
โโข Laravel โ Full-Stack Web
โโข Symfony โ Web Framework
โโข PHPUnit โ Testing
โฏ Go (Golang)
โโข Gin โ Web Framework
โโข Gorilla โ Web Toolkit
โโข GORM โ ORM for Go
โฏ Rust
โโข Actix โ Web Framework
โโข Rocket โ Web Development
โโข Tokio โ Async Runtime
Coding Resources: https://whatsapp.com/channel/0029VahiFZQ4o7qN54LTzB17
React with โค๏ธ for more useful content
โฏ Python
โโข Pandas โ Data Analysis
โโข NumPy โ Math & Arrays
โโข Scikit-learn โ Machine Learning
โโข TensorFlow / PyTorch โ Deep Learning
โโข Flask / Django โ Web Development
โโข OpenCV โ Image Processing
โฏ JavaScript / TypeScript
โโข React โ UI Development
โโข Vue โ Lightweight SPAs
โโข Angular โ Enterprise Apps
โโข Next.js โ Full-Stack Web
โโข Express โ Backend APIs
โโข Three.js โ 3D Web Graphics
โฏ Java
โโข Spring Boot โ Microservices
โโข Hibernate โ ORM
โโข Apache Maven โ Build Automation
โโข Apache Kafka โ Real-Time Data
โฏ C++
โโข Boost โ Utility Libraries
โโข Qt โ GUI Applications
โโข Unreal Engine โ Game Development
โฏ C#
โโข .NET / ASP.NET โ Web Apps
โโข Unity โ Game Development
โโข Entity Framework โ ORM
โฏ R
โโข ggplot2 โ Data Visualization
โโข dplyr โ Data Manipulation
โโข caret โ Machine Learning
โโข Shiny โ Interactive Dashboards
โฏ PHP
โโข Laravel โ Full-Stack Web
โโข Symfony โ Web Framework
โโข PHPUnit โ Testing
โฏ Go (Golang)
โโข Gin โ Web Framework
โโข Gorilla โ Web Toolkit
โโข GORM โ ORM for Go
โฏ Rust
โโข Actix โ Web Framework
โโข Rocket โ Web Development
โโข Tokio โ Async Runtime
Coding Resources: https://whatsapp.com/channel/0029VahiFZQ4o7qN54LTzB17
React with โค๏ธ for more useful content
โค2
Interviewer: You have 2 minutes. Explain the JavaScript Event Loop to me.
My answer: Challenge accepted, letโs go!
โค Single-Threaded Execution:
JavaScript is single-threaded, which means it can only execute one task at a time. This is managed by the call stack, where functions are executed one by one.
โค Call Stack: Think of the call stack as a stack of plates. Every time a function is called, a new plate (function) is added to the stack. When the function finishes, the plate is removed from the stack.
โค Web APIs: For asynchronous operations like
โค Callback Queue: When an asynchronous operation completes, its callback is placed in the callback queue. This queue waits until the call stack is clear before pushing the next callback onto the stack.
โค Event Loop: The event loop is like a manager that constantly checks if the call stack is empty. When it is, the event loop takes the first callback from the callback queue and adds it to the call stack.
โค Microtasks Queue: There's also a microtasks queue for tasks like promises. This queue has higher priority than the callback queue. The event loop checks the microtasks queue first, ensuring these tasks are processed before other callbacks.
โค Priority Handling: To sum it up, the event loop first checks the microtasks queue. If it's empty, it moves to the callback queue. This ensures that critical tasks, like promises, are handled promptly.
Thatโs the JavaScript Event Loop.
Timeโs up..
My answer: Challenge accepted, letโs go!
โค Single-Threaded Execution:
JavaScript is single-threaded, which means it can only execute one task at a time. This is managed by the call stack, where functions are executed one by one.
โค Call Stack: Think of the call stack as a stack of plates. Every time a function is called, a new plate (function) is added to the stack. When the function finishes, the plate is removed from the stack.
โค Web APIs: For asynchronous operations like
setTimeout
, DOM events, and HTTP requests, JavaScript relies on Web APIs provided by the browser. These operations are handled outside of the call stack.โค Callback Queue: When an asynchronous operation completes, its callback is placed in the callback queue. This queue waits until the call stack is clear before pushing the next callback onto the stack.
โค Event Loop: The event loop is like a manager that constantly checks if the call stack is empty. When it is, the event loop takes the first callback from the callback queue and adds it to the call stack.
โค Microtasks Queue: There's also a microtasks queue for tasks like promises. This queue has higher priority than the callback queue. The event loop checks the microtasks queue first, ensuring these tasks are processed before other callbacks.
โค Priority Handling: To sum it up, the event loop first checks the microtasks queue. If it's empty, it moves to the callback queue. This ensures that critical tasks, like promises, are handled promptly.
Thatโs the JavaScript Event Loop.
Timeโs up..
โค8
Starting with coding is a fantastic foundation for a tech career. As you grow your skills, you might explore various areas depending on your interests and goals:
โข Web Development: If you enjoy building websites and web applications, diving into web development could be your next step. You can specialize in front-end (HTML, CSS, JavaScript) or back-end (Python, Java, Node.js) development, or become a full-stack developer.
โข Mobile App Development: If you're excited about creating apps for smartphones and tablets, you might explore mobile development. Learn Swift for iOS or Kotlin for Android, or use cross-platform tools like Flutter or React Native.
โข Data Science and Analysis: If analyzing and interpreting data intrigues you, focusing on data science or data analysis could be your path. You'll use languages like Python or R and tools like Pandas, NumPy, and SQL.
โข Game Development: If youโre passionate about creating games, you might explore game development. Languages like C# with Unity or C++ with Unreal Engine are popular choices in this field.
โข Cybersecurity: If you're interested in protecting systems from threats, diving into cybersecurity could be a great fit. Learn about ethical hacking, penetration testing, and security protocols.
โข Software Engineering: If you enjoy designing and building complex software systems, focusing on software engineering might be your calling. This involves writing code, but also planning, testing, and maintaining software.
โข Automation and Scripting: If you're interested in making repetitive tasks easier, scripting and automation could be a good path. Python, Bash, and PowerShell are popular for writing scripts to automate tasks.
โข Artificial Intelligence and Machine Learning: If you're fascinated by creating systems that learn and adapt, exploring AI and machine learning could be your next step. Youโll work with algorithms, data, and models to create intelligent systems.
Regardless of the path you choose, the key is to keep coding, learning, and challenging yourself with new projects. Each step forward will deepen your understanding and open new opportunities in the tech world.
โข Web Development: If you enjoy building websites and web applications, diving into web development could be your next step. You can specialize in front-end (HTML, CSS, JavaScript) or back-end (Python, Java, Node.js) development, or become a full-stack developer.
โข Mobile App Development: If you're excited about creating apps for smartphones and tablets, you might explore mobile development. Learn Swift for iOS or Kotlin for Android, or use cross-platform tools like Flutter or React Native.
โข Data Science and Analysis: If analyzing and interpreting data intrigues you, focusing on data science or data analysis could be your path. You'll use languages like Python or R and tools like Pandas, NumPy, and SQL.
โข Game Development: If youโre passionate about creating games, you might explore game development. Languages like C# with Unity or C++ with Unreal Engine are popular choices in this field.
โข Cybersecurity: If you're interested in protecting systems from threats, diving into cybersecurity could be a great fit. Learn about ethical hacking, penetration testing, and security protocols.
โข Software Engineering: If you enjoy designing and building complex software systems, focusing on software engineering might be your calling. This involves writing code, but also planning, testing, and maintaining software.
โข Automation and Scripting: If you're interested in making repetitive tasks easier, scripting and automation could be a good path. Python, Bash, and PowerShell are popular for writing scripts to automate tasks.
โข Artificial Intelligence and Machine Learning: If you're fascinated by creating systems that learn and adapt, exploring AI and machine learning could be your next step. Youโll work with algorithms, data, and models to create intelligent systems.
Regardless of the path you choose, the key is to keep coding, learning, and challenging yourself with new projects. Each step forward will deepen your understanding and open new opportunities in the tech world.
โค6
*You can learn ReactJS easily ๐คฉ*
Here's all you need to get started ๐
1.Components
โข Functional Components
โข Class Components
โข JSX (JavaScript XML) Syntax
2.Props (Properties)
โข Passing Props
โข Default Props
โข Prop Types
3.State
โข useState Hook
โข Class Component State
โข Immutable State
4.Lifecycle Methods (Class Components)
โข componentDidMount
โข componentDidUpdate
โข componentWillUnmount
5.Hooks (Functional Components)
โข useState
โข useEffect
โข useContext
โข useReducer
โข useCallback
โข useMemo
โข useRef
โข useImperativeHandle
โข useLayoutEffect
6.Event Handling
โข Handling Events in Functional Components
โข Handling Events in Class Components
7.Conditional Rendering
โข if Statements
โข Ternary Operators
โข Logical && Operator
8.Lists and Keys
โข Rendering Lists
โข Keys in React Lists
9.Component Composition
โข Reusing Components
โข Children Props
โข Composition vs Inheritance
10.Higher-Order Components (HOC)
โข Creating HOCs
โข Using HOCs for Reusability
11.Render Props
โข Using Render Props Pattern
12.React Router
โข <BrowserRouter>
โข <Route>
โข <Link>
โข <Switch>
โข Route Parameters
13.Navigation
โข useHistory Hook
โข useLocation Hook
State Management
14.Context API
โข Creating Context
โข useContext Hook
15.Redux
โข Actions
โข Reducers
โข Store
โข connect Function (React-Redux)
16.Forms
โข Handling Form Data
โข Controlled Components
โข Uncontrolled Components
17.Side Effects
โข useEffect for Data Fetching
โข useEffect Cleanup
18.AJAX Requests
โข Fetch API
โข Axios Library
Error Handling
19.Error Boundaries
โข componentDidCatch (Class Components)
โข ErrorBoundary Component (Functional
Components)
20.Testing
โข Jest Testing Framework
โข React Testing Library
21. Best Practices
โข Code Splitting
โข PureComponent and React.iss.onemo
โข Avoiding Reconciliation
โข Keys for Dynamic Lists
22.Optimization
โข Memoization
โข Profiling and Performance Monitoring
23. Build and Deployment
โข Create React App (CRA)
โข Production Builds
โข Deployment Strategies
Frameworks and Libraries
24.Styling Libraries
โข Styled-components
โข CSS Modules
25.State Management Libraries
โข Redux
โข MobX
26.Routing Libraries
โข React Router
โข Reach Router
Here's all you need to get started ๐
1.Components
โข Functional Components
โข Class Components
โข JSX (JavaScript XML) Syntax
2.Props (Properties)
โข Passing Props
โข Default Props
โข Prop Types
3.State
โข useState Hook
โข Class Component State
โข Immutable State
4.Lifecycle Methods (Class Components)
โข componentDidMount
โข componentDidUpdate
โข componentWillUnmount
5.Hooks (Functional Components)
โข useState
โข useEffect
โข useContext
โข useReducer
โข useCallback
โข useMemo
โข useRef
โข useImperativeHandle
โข useLayoutEffect
6.Event Handling
โข Handling Events in Functional Components
โข Handling Events in Class Components
7.Conditional Rendering
โข if Statements
โข Ternary Operators
โข Logical && Operator
8.Lists and Keys
โข Rendering Lists
โข Keys in React Lists
9.Component Composition
โข Reusing Components
โข Children Props
โข Composition vs Inheritance
10.Higher-Order Components (HOC)
โข Creating HOCs
โข Using HOCs for Reusability
11.Render Props
โข Using Render Props Pattern
12.React Router
โข <BrowserRouter>
โข <Route>
โข <Link>
โข <Switch>
โข Route Parameters
13.Navigation
โข useHistory Hook
โข useLocation Hook
State Management
14.Context API
โข Creating Context
โข useContext Hook
15.Redux
โข Actions
โข Reducers
โข Store
โข connect Function (React-Redux)
16.Forms
โข Handling Form Data
โข Controlled Components
โข Uncontrolled Components
17.Side Effects
โข useEffect for Data Fetching
โข useEffect Cleanup
18.AJAX Requests
โข Fetch API
โข Axios Library
Error Handling
19.Error Boundaries
โข componentDidCatch (Class Components)
โข ErrorBoundary Component (Functional
Components)
20.Testing
โข Jest Testing Framework
โข React Testing Library
21. Best Practices
โข Code Splitting
โข PureComponent and React.iss.onemo
โข Avoiding Reconciliation
โข Keys for Dynamic Lists
22.Optimization
โข Memoization
โข Profiling and Performance Monitoring
23. Build and Deployment
โข Create React App (CRA)
โข Production Builds
โข Deployment Strategies
Frameworks and Libraries
24.Styling Libraries
โข Styled-components
โข CSS Modules
25.State Management Libraries
โข Redux
โข MobX
26.Routing Libraries
โข React Router
โข Reach Router
โค2
Typical C++ interview questions sorted by experience
Junior:
- What are the key features of object-oriented programming in C++?
- Explain the differences between public, private, and protected access specifiers in C++.
- Distinguish between function overloading and overriding in C++.
- Compare and contrast abstract classes and interfaces in C++.
- Can an interface inherit from another interface in C++?
- Define the static keyword in C++ and its significance.
- Is it possible to override a static method in C++?
- Explain the concepts of polymorphism and inheritance in C++.
- Can constructors be inherited in C++?
- Discuss pass-by-reference and pass-by-value for objects in C++.
- Compare == and .equals for string comparison in C++.
- Explain the purposes of the hashCode() and equals() functions.
- What does the Serializable interface do? How is it related to Parcelable in Android?
- Differentiate between Array and ArrayList in C++. When would you use each?
- Explain the distinction between Integer and int in C++.
- Define ThreadPool and discuss its advantages over using simple threads.
- Differentiate between local, instance, and class variables in C++.
Mid:
- What is reflection in C++?
- Define dependency injection and name a few libraries. Have you used any?
- Explain strong, soft, and weak references in C++.
- Interpret the meaning of the synchronized keyword.
- Can memory leaks occur in C++?
- Is it necessary to set references to null in C++?
- Why is a String considered immutable?
- Discuss transient and volatile modifiers in C++.
- What is the purpose of the finalize() method?
- How does the try{} finally{} block work in C++?
- Explain the difference between object instantiation and initialization.
- Under what conditions is a static block executed in C++?
- Why are generics used in C++?
- Mention some design patterns you are familiar with. Which do you typically use?
- Name some types of testing methodologies in C++.
Senior:
- Explain how
- What is the "double-check locking" problem, and how can it be solved in C++?
- Differentiate between StringBuffer and StringBuilder in C++.
- How is StringBuilder implemented to avoid the immutable string allocation problem?
- Explain the purpose of the
- Define Autoboxing and Unboxing in C++.
- What's the difference between Enumeration and Iterator in C++?
- Explain the difference between fail-fast and fail-safe in C++.
- What is PermGen in C++?
- Describe a Java priority queue.
- How is performance influenced by using the same number in different types: Int, Double, and Float?
- Explain the concept of the Java Heap.
- What is a daemon thread?
- Can a dead thread be restarted in C++?
โ Best Telegram channels to get free coding & data science resources
-> https://t.iss.one/addlist/4q2PYC0pH_VjZDk5
ENJOY LEARNING ๐๐
Junior:
- What are the key features of object-oriented programming in C++?
- Explain the differences between public, private, and protected access specifiers in C++.
- Distinguish between function overloading and overriding in C++.
- Compare and contrast abstract classes and interfaces in C++.
- Can an interface inherit from another interface in C++?
- Define the static keyword in C++ and its significance.
- Is it possible to override a static method in C++?
- Explain the concepts of polymorphism and inheritance in C++.
- Can constructors be inherited in C++?
- Discuss pass-by-reference and pass-by-value for objects in C++.
- Compare == and .equals for string comparison in C++.
- Explain the purposes of the hashCode() and equals() functions.
- What does the Serializable interface do? How is it related to Parcelable in Android?
- Differentiate between Array and ArrayList in C++. When would you use each?
- Explain the distinction between Integer and int in C++.
- Define ThreadPool and discuss its advantages over using simple threads.
- Differentiate between local, instance, and class variables in C++.
Mid:
- What is reflection in C++?
- Define dependency injection and name a few libraries. Have you used any?
- Explain strong, soft, and weak references in C++.
- Interpret the meaning of the synchronized keyword.
- Can memory leaks occur in C++?
- Is it necessary to set references to null in C++?
- Why is a String considered immutable?
- Discuss transient and volatile modifiers in C++.
- What is the purpose of the finalize() method?
- How does the try{} finally{} block work in C++?
- Explain the difference between object instantiation and initialization.
- Under what conditions is a static block executed in C++?
- Why are generics used in C++?
- Mention some design patterns you are familiar with. Which do you typically use?
- Name some types of testing methodologies in C++.
Senior:
- Explain how
std::stoi
(string to integer) works in C++.- What is the "double-check locking" problem, and how can it be solved in C++?
- Differentiate between StringBuffer and StringBuilder in C++.
- How is StringBuilder implemented to avoid the immutable string allocation problem?
- Explain the purpose of the
Class.forName
method in C++.- Define Autoboxing and Unboxing in C++.
- What's the difference between Enumeration and Iterator in C++?
- Explain the difference between fail-fast and fail-safe in C++.
- What is PermGen in C++?
- Describe a Java priority queue.
- How is performance influenced by using the same number in different types: Int, Double, and Float?
- Explain the concept of the Java Heap.
- What is a daemon thread?
- Can a dead thread be restarted in C++?
โ Best Telegram channels to get free coding & data science resources
-> https://t.iss.one/addlist/4q2PYC0pH_VjZDk5
ENJOY LEARNING ๐๐
โค1
Top linked list questions to practice:
1. ๐ Reverse a Linked List
2. ๐ Detect a Cycle in a Linked List
3. ๐ค Find the Merge Point of Two Linked Lists
4. ๐ซ Remove N-th Node From End of List
5. ๐ Merge Two Sorted Linked Lists
6. ๐ผ๏ธ Check if a Linked List is a Palindrome
7. ๐จ Remove Duplicates from a Sorted List
8. ๐ฏ Find the Middle of a Linked List
9. ๐ Rotate a Linked List
10. ๐ Implement a Doubly Linked List
11. ๐ Implement a Circular Linked List
12. ๐ ๏ธ Add Two Numbers Represented by Linked Lists
13. ๐งน Remove Linked List Elements
14. ๐งฉ Partition List around a value
15. ๐ Reverse Nodes in k-Group
1. ๐ Reverse a Linked List
2. ๐ Detect a Cycle in a Linked List
3. ๐ค Find the Merge Point of Two Linked Lists
4. ๐ซ Remove N-th Node From End of List
5. ๐ Merge Two Sorted Linked Lists
6. ๐ผ๏ธ Check if a Linked List is a Palindrome
7. ๐จ Remove Duplicates from a Sorted List
8. ๐ฏ Find the Middle of a Linked List
9. ๐ Rotate a Linked List
10. ๐ Implement a Doubly Linked List
11. ๐ Implement a Circular Linked List
12. ๐ ๏ธ Add Two Numbers Represented by Linked Lists
13. ๐งน Remove Linked List Elements
14. ๐งฉ Partition List around a value
15. ๐ Reverse Nodes in k-Group
โค3
1. Does SQL support programming language features?
It is true that SQL is a language, but it does not support programming as it is not a programming language, it is a command language. We do not have some programming concepts in SQL like for loops or while loop, we only have commands which we can use to query, update, delete, etc. data in the database. SQL allows us to manipulate data in a database.
2. What is a trigger?
Trigger is a statement that a system executes automatically when there is any modification to the database. In a trigger, we first specify when the trigger is to be executed and then the action to be performed when the trigger executes. Triggers are used to specify certain integrity constraints and referential constraints that cannot be specified using the constraint mechanism of SQL.
3. What are aggregate and scalar functions?
For doing operations on data SQL has many built-in functions, they are categorized into two categories and further sub-categorized into seven different functions under each category. The categories are:
Aggregate functions:
These functions are used to do operations from the values of the column and a single value is returned.
Scalar functions:
These functions are based on user input, these too return a single value.
4. Define SQL Order by the statement?
The ORDER BY statement in SQL is used to sort the fetched data in either ascending or descending according to one or more columns.
By default ORDER BY sorts the data in ascending order.
We can use the keyword DESC to sort the data in descending order and the keyword ASC to sort in ascending order.
5. What is the difference between primary key and unique constraints?
The primary key cannot have NULL values, the unique constraints can have NULL values. There is only one primary key in a table, but there can be multiple unique constraints. The primary key creates the clustered index automatically but the unique key does not.
It is true that SQL is a language, but it does not support programming as it is not a programming language, it is a command language. We do not have some programming concepts in SQL like for loops or while loop, we only have commands which we can use to query, update, delete, etc. data in the database. SQL allows us to manipulate data in a database.
2. What is a trigger?
Trigger is a statement that a system executes automatically when there is any modification to the database. In a trigger, we first specify when the trigger is to be executed and then the action to be performed when the trigger executes. Triggers are used to specify certain integrity constraints and referential constraints that cannot be specified using the constraint mechanism of SQL.
3. What are aggregate and scalar functions?
For doing operations on data SQL has many built-in functions, they are categorized into two categories and further sub-categorized into seven different functions under each category. The categories are:
Aggregate functions:
These functions are used to do operations from the values of the column and a single value is returned.
Scalar functions:
These functions are based on user input, these too return a single value.
4. Define SQL Order by the statement?
The ORDER BY statement in SQL is used to sort the fetched data in either ascending or descending according to one or more columns.
By default ORDER BY sorts the data in ascending order.
We can use the keyword DESC to sort the data in descending order and the keyword ASC to sort in ascending order.
5. What is the difference between primary key and unique constraints?
The primary key cannot have NULL values, the unique constraints can have NULL values. There is only one primary key in a table, but there can be multiple unique constraints. The primary key creates the clustered index automatically but the unique key does not.
โค1
SQL (Structured Query Language) is a standard programming language used to manage and manipulate relational databases. Here are some key concepts to understand the basics of SQL:
1. Database: A database is a structured collection of data organized in tables, which consist of rows and columns.
2. Table: A table is a collection of related data organized in rows and columns. Each row represents a record, and each column represents a specific attribute or field.
3. Query: A SQL query is a request for data or information from a database. Queries are used to retrieve, insert, update, or delete data in a database.
4. CRUD Operations: CRUD stands for Create, Read, Update, and Delete. These are the basic operations performed on data in a database using SQL:
- Create (INSERT): Adds new records to a table.
- Read (SELECT): Retrieves data from one or more tables.
- Update (UPDATE): Modifies existing records in a table.
- Delete (DELETE): Removes records from a table.
5. Data Types: SQL supports various data types to define the type of data that can be stored in each column of a table, such as integer, text, date, and decimal.
6. Constraints: Constraints are rules enforced on data columns to ensure data integrity and consistency. Common constraints include:
- Primary Key: Uniquely identifies each record in a table.
- Foreign Key: Establishes a relationship between two tables.
- Unique: Ensures that all values in a column are unique.
- Not Null: Specifies that a column cannot contain NULL values.
7. Joins: Joins are used to combine rows from two or more tables based on a related column between them. Common types of joins include INNER JOIN, LEFT JOIN (or LEFT OUTER JOIN), RIGHT JOIN (or RIGHT OUTER JOIN), and FULL JOIN (or FULL OUTER JOIN).
8. Aggregate Functions: SQL provides aggregate functions to perform calculations on sets of values. Common aggregate functions include SUM, AVG, COUNT, MIN, and MAX.
9. Group By: The GROUP BY clause is used to group rows that have the same values into summary rows. It is often used with aggregate functions to perform calculations on grouped data.
10. Order By: The ORDER BY clause is used to sort the result set of a query based on one or more columns in ascending or descending order.
Understanding these basic concepts of SQL will help you write queries to interact with databases effectively. Practice writing SQL queries and experimenting with different commands to become proficient in using SQL for database management and manipulation.
SQL Learning Series: https://whatsapp.com/channel/0029VanC5rODzgT6TiTGoa1v/1075
1. Database: A database is a structured collection of data organized in tables, which consist of rows and columns.
2. Table: A table is a collection of related data organized in rows and columns. Each row represents a record, and each column represents a specific attribute or field.
3. Query: A SQL query is a request for data or information from a database. Queries are used to retrieve, insert, update, or delete data in a database.
4. CRUD Operations: CRUD stands for Create, Read, Update, and Delete. These are the basic operations performed on data in a database using SQL:
- Create (INSERT): Adds new records to a table.
- Read (SELECT): Retrieves data from one or more tables.
- Update (UPDATE): Modifies existing records in a table.
- Delete (DELETE): Removes records from a table.
5. Data Types: SQL supports various data types to define the type of data that can be stored in each column of a table, such as integer, text, date, and decimal.
6. Constraints: Constraints are rules enforced on data columns to ensure data integrity and consistency. Common constraints include:
- Primary Key: Uniquely identifies each record in a table.
- Foreign Key: Establishes a relationship between two tables.
- Unique: Ensures that all values in a column are unique.
- Not Null: Specifies that a column cannot contain NULL values.
7. Joins: Joins are used to combine rows from two or more tables based on a related column between them. Common types of joins include INNER JOIN, LEFT JOIN (or LEFT OUTER JOIN), RIGHT JOIN (or RIGHT OUTER JOIN), and FULL JOIN (or FULL OUTER JOIN).
8. Aggregate Functions: SQL provides aggregate functions to perform calculations on sets of values. Common aggregate functions include SUM, AVG, COUNT, MIN, and MAX.
9. Group By: The GROUP BY clause is used to group rows that have the same values into summary rows. It is often used with aggregate functions to perform calculations on grouped data.
10. Order By: The ORDER BY clause is used to sort the result set of a query based on one or more columns in ascending or descending order.
Understanding these basic concepts of SQL will help you write queries to interact with databases effectively. Practice writing SQL queries and experimenting with different commands to become proficient in using SQL for database management and manipulation.
SQL Learning Series: https://whatsapp.com/channel/0029VanC5rODzgT6TiTGoa1v/1075
โค5๐ฅฐ1