What is node.js?
Node.js is a runtime environment that allows developers to run JavaScript code on the server side, outside of a browser.
Node.js uses Google's V8 engine, which compiles JavaScript into native machine code, ensuring high performance.
Node.js operates on a single-threaded event loop, making it highly efficient for handling multiple simultaneous requests without blocking the execution.
JavaScript was used only for client-side scripting (in browsers). Node.js enables JavaScript to be used for building back-end applications, such as APIs and web servers.
Node.js comes with NPM (Node Package Manager), the world's largest ecosystem of open-source libraries, making it easy to reuse code and extend functionality.
How node.js is a runtime environment on the server side ? and what is v8?
browser execute javaScript on the client side and similarly node.js execute javaScript on the server side.
Node.js acts as the environment where JavaScript code interacts directly with the server's operating system, files, and network resources, similar to how a browser provides an environment for client-side JavaScript.
V8 is a javascript engine for the javascript language.
Node.js uses V8 to execute JavaScript code but adds additional features (e.g., libraries for file I/O, HTTP, and networking) that JavaScript alone doesn’t provide.
V8 handles the core JavaScript execution, such as variable handling, loops, and JavaScript functions.
Node.js builds upon V8 to enable server-side capabilities.
Browser vs Node.js:
- Browser: Executes JavaScript on the client side for rendering webpages, interacting with the DOM, and handling user input.
- Node.js: Executes JavaScript on the server side, handling tasks like serving web pages, accessing databases, and managing APIs.
In short:
- Node.js: A runtime environment that executes JavaScript on the server side.
- V8: The JavaScript engine powering both Node.js and Chrome for executing JavaScript efficiently.
What is the different between a run time environment and a framework
A runtime environment (e.g., Node.js) provides the necessary tools and libraries to execute code in a specific language, managing tasks like memory, I/O, and execution.
A framework (e.g., Express.js) provides a structured way to build applications by offering predefined patterns, tools, and libraries to streamline development.
In short:
- Runtime environment: Executes code.
- Framework: Provides a structure for building applications.
What is the difference between Node.js and Exoress.js
Node.js is a runtime environment that executes JavaScript on the server side and provides core modules for handling tasks like file I/O, HTTP, and networking.
Express.js is a web framework built on top of Node.js that simplifies building web applications and APIs by providing features like routing, middleware, and request handling.
Combining Node.js and Express.js makes building server-side APIs simple and efficient.
In short:
- Node.js: Executes JavaScript and provides the core tools.
- Express.js: Adds structure and tools for building web apps and APIs.
What is the differences between client side(Browser) and Server side(Node.js)
Client Side (Browser):
- Executes JavaScript in the browser.
- Handles user interface, DOM manipulation, and user interactions.
- Cannot access server resources like databases or the file system directly.
Server Side (Node.js):
- Executes JavaScript on the server.
- Handles backend logic, database operations, and API requests.
- Can access server resources like files, databases, and network service.
What are the 7 main features of Node.js
Asynchronous and Event-Driven:
- Non-blocking I/O operations allow handling multiple requests simultaneously.
Single-Threaded with Event Loop:
- Efficiently manages concurrency using a single thread and an event loop.
Fast Execution:
- Built on Google’s V8 engine, it compiles JavaScript into machine code for high performance.
Scalability:
- Designed to handle a large number of concurrent connections with low resource usage.
Cross-Platform:
- Runs on Windows, macOS, and Linux, making it versatile for deployment.
Rich NPM Ecosystem:
- Provides access to thousands of open-source packages through Node Package Manager (NPM).
Streaming Data:
- Efficiently processes streams of data, making it ideal for real-time applications.
Single-threaded programming: What is it?
In single-threaded programming, a program does all its work in a single stream of execution. This thread performs one task at a time, in sequence.
Single-Threaded Programming Features:
Single Execution Flow.
Limited Parallelism.
Event Loop in Node.js.
Synchronous and Asynchronous Programming. What Is It?
Definition: A sequence of tasks will be executed one by one in the order they were requested. The next task can only start after the previous one has finished.
Blocking Nature: A task may block the program until it is done.
When to use it: Based on a simple workflow, where tasks are dependent on previous task completion.
Asynchronous Programming:
Definition: Tasks can begin and continue without waiting for other tasks to complete. We rely on callbacks, promises or async/await to handle results for tasks that have been completed.
Non-Blocking: When a task is executed, it does not block program execution, allowing other tasks to run in parallel.
Use Case: Best for operations like file I/O, API calls, or database queries where waiting would waste resources.
What is Multi-Threaded Programming?
Multi-threading programming The multi-threading programming is a programming model which will run several threads within a process.
main features of multi-threaded programming:
Multiple Threads:
Threads can execute independently but share the same memory and resources of the parent process.
Parallelism:
This allows tasks to run simultaneously on different threads and makes use of multi-core CPUs.
Concurrency:
Even if not executed in parallel (for instance, by means of thread scheduling).
Resource Sharing:
Threads have the ability to share data and memory, resulting in faster communication between threads, though they must be synchronized to avoid race conditions.
Advantages of Multi-Threaded Programming:
Performance
Responsiveness
Efficient Resource Use
Challenges:
Complexity
Race Conditions
Deadlocks
What are Events, Event Emitter, Event Queue, Event Loop, Event Handler, and Event Driven in node.js
Events | Actions like file read, user request, or server response. |
Event Emitter | Class to create, emit, and handle custom events. |
Event Queue | Events emitted Queue (stored in event queue). |
Event Loop | Mechanism that processes the event queue and executes tasks.The event loop picksup event from the event queue and execute them in the order they were added |
Event Driven | A programming model driven by events and their callbacks. |
What are the Disadvantages of Node.js? When to use and When not to use.
Disadvantages of Node.js:
Single-Threaded Limitation:
Node. js is single-threaded and has an event loop that may have performance issues in CPU-bound tasks such as complex computations or heavy data processing.
Callback Hell:
When you have lots of nested callbacks in your asynchronous code, it can often become difficult to read and maintain.
Promised or async/await mitigated.
Limited Performance for CPU-Intensive Workloads:
Node. js are built for I/O bound not CPU bound. CPU intensive tasks can block the event loop and will reduce performance.
Lack of a Strong Type:
Node. js lacks a built-in type system, which makes it prone to runtime errors. You can use TypeScript to solve this problem.
Maturity of Modules:
There are indeed a wealth of third-party modules, with some being poorly supported with no documentation.
Unstable API:
Some Node. Frequent updates to js introduce breaking changes and often require code to change.
When to Use Node.js:
Real-Time Applications:
Applications that demand low latency and instant information such as chat apps, online gaming, and collaboration tools.
API Development:
RESTful or GraphQL APIs with significant scalability needs
Streaming Applications:
Platforms for streaming video, audio, or files.
Microservices:
Node. js is a lightweight framework to develop the small and independent services.
TOP 5 TRENDS IN REACT DEVELOPMENT :
Single-Page Applications (SPAs)
Backend for SPAs that deal with async data.
Event-Driven Applications:
Data on device models (e.g., for use in forecasting).
When NOT to Use Node.js:
CPU-Intensive Applications:
Heavy computational applications — examples include video encoding, scientific simulations, or even machine learning.
Monolithic Applications:
Massive, tightly coupled systems where multi-threading is a necessity.
Low-Latency Applications:
For systems that require stable and predictable response times during heavy CPU usage.
Applications that Require Multithreading:
Use Multithreading in an environment with better support like JAVA or PYTHON
What is npm ?
npm(node package manager) is a tool that comes with Node.js and is used for managing the Javascript packages and dependencies for our node project.
What is node_module ?
node_module folder contains all the dependencies of the node project.
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