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:
- Websites – React.js, Angular, jQuery, and many more.
- Backend Systems – Node.js.
- Persistence (Database) – MongoDB.
- Mobile, and Desktop applications.
How does the Node.js framework works??
The Node.js framework works based on four different concepts in its architecture:
- Non-blocking operations.
- Callback mechanism.
- Event loop.
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.
- 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.
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.
Node.js optimizes these processes through some sophisticated processes like code inlining and copy elision, among others.
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.