In addition to this, the Nodejs platform is a single-threaded language that greatly broadened its scope in web application development and becomes a much feasible browser scripting language.
Few of the real developmental scenarios of Nodejs are:
- Websites – React.js, Angular, jQuery, and many more.
- Backend Systems – Nodejs.
- Persistence (Database) – MongoDB.
- Mobile, and Desktop applications.
How does the Nodejs platform work?
The Nodejs platform works based on four different concepts in its architecture:
- Non-blocking operations.
- Callback mechanism.
- Event loop.
Nodejs is all about non-blocking and perfect asynchronous architecture. Eventually, it 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 return through a callback function.
- The main thread won’t block 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 the successful execution of a process.
In simple, a callback function is generally called at the end of any given task. Nodejs makes heavy use of callbacks than others. All the Application Programming Interface(APIs) of the Nodejs platform are in such a way that all they support callback functions.
Nodejs platform optimizes these processes through some sophisticated processes like code in-lining and a copy elision, among others.
One of the main reasons for such lighting fast speed of Nodejs platform is its Event loop model. And it reaches such speed as it uses events heavily. It is pretty fast when compared with other similar technologies. As Nodejs starts, it simply initiates its variables and declares functions. Then which relates 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 on the observer pattern. The functions that listen to events act as Observers in the event loop concept. Thus, Nodejs has multiple in-built events that are available through events module and EventEmitter class which is to bind events and event-listeners.