How does the Node.js framework works??

Node.js is a popular framework for building backend systems like network applications with great scaling features. Node.js is a Javascript run-time environment, which means it runs the JavaScript codes.

Javascript is a long-standing programming language used in webpages and run by any web browsers. As of now, the Javascript can also run without a browser which made possible using Node.js which uses Google Chrome’s V8 JavaScript engine.

Wondering how a scripting language(Javascript) can be used for developing web applications. As we all know that a bindle of compiled codes is much more efficient than the interpreted scripts. 

In addition to this, Node.js is a single-threaded language that greatly broadened its scope in web application development and becomes a much feasible browser scripting language. Now, it is being used in frameworks with different scenarios.

Few of the real developmental scenarios of Node.js are listed below:

  1. Websites – React.js, Angular, jQuery, and many more.
  2. Backend Systems – Node.js.
  3. Persistence (Database) – MongoDB.
  4. Mobile, and Desktop applications.

How does the Node.js framework works??

The Node.js framework works based on four different concepts in its architecture:

  1. Non-blocking operations.
  2. Callback mechanism.
  3. V8 Javascript engine.
  4. Event loop.

Non-blocking operations

Node.js is all about non-blocking and asynchronous architecture. This means any operations that really take a long time to finish like file access, network communication, and database operations, are requested and put on hold until the results are ready and returned through a callback function.

In JavaScript, another approach is used with callbacks. When the operation is completed, a non-blocking call in JavaScript provides a callback function to indicate task completion.

In simple,

  • The main thread won’t be blocked in any input/output operations.
  • The server will keep working on upcoming requests.
  • It works with asynchronous code every single time.

Callback mechanism

A callback is an asynchronous equivalent for a function mostly. An asynchronous function has the functionality to call all the events when they complete the execution. The asynchronous function does not wait for any task to complete, it continues its execution process.

Callback function is a function that is called automatically after the completion of successful execution of a process.

In simple, a callback function is generally called at the end of any given task. Node.js makes heavy use of callbacks than others. All the Application Programming Interface(APIs) of Node.js are written in such a way that all they support callback functions.

V8 Javascript engine

Node.js uses the ultra-fast Google Chrome’s V8 execution engine. During its release, the V8 engine grabbed the attention of developers around the world, because it’s an open-source tool created by Google which analyses and runs JavaScript code very quickly.

Until the inception of Chrome’s V8, most browsers fail to read the JavaScript inefficiently: the code was read and interpreted bit by bit. Here in Node.js, it uses Google Chrome’s V8 engine which completely works differently from others. It is a highly optimized structure that carries out JIT (Just In Time) kind of compilation. It quickly transforms the way how JavaScript code turns into machine language.

Node.js optimizes these processes through some sophisticated processes like code inlining and copy elision, among others.

Event loop

One of the main reasons for such lighting fast speed of Node.js just because it uses events heavily. It is pretty fast when compared to other similar technologies. As Node.js starts, it simply initiates its variables and declares functions related to processing then simply waits for the event to occur continuously.

In an event-driven application, If any events are been detected then the main loop that waits for events, and triggers a respective callback function.

Although events look similar to callbacks, the key difference between that callback function is called when an asynchronous function returns its result obtained on the observer pattern. The functions that listen to events act as Observers in the event loop concept. Thus, Node.js has multiple in-built events that are available through events module and EventEmitter class which is used to bind events and event-listeners.

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