Comparing synchronous and asynchronous streams in RxJS

I have a basic question regarding the distinction between synchronous and asynchronous operators and sequences.

In programming, everything can be represented as a sequence. For example:

An array of numbers can be considered a sequence that is traditionally processed synchronously using functions like reduce to calculate a sum or average where all elements need to be known in advance.
An array of click events are examples of an asynchronous sequence which may come in the future with unknown arrival times and quantities.

The Observable datatype allows for various operations on elements in a sequence such as merge, zip, and more.

RxJS treats sequences asynchronously. So my question is - what's the purpose of operators like average, count, max, min, reduce, etc., that require the sequence to be completed? If we cannot asynchronously add elements to a sequence for recalculations, why choose RxJS over Array.prototype.reduce?

In essence, I initially thought that sequences should be operable (regardless of the operation) even when they are incomplete.

Answer №1

It was mentioned previously that Rx is beneficial for handling asynchronous events. While the Array method can be used for reduce, it requires either recalculating from the start or storing and accumulating values to perform a single reduce operation on new values.

With RxJS, the accumulated value is stored in the observable created by the .reduce method, automatically applying methods when new values arrive.

For operations like count, max, and min, they act as filter methods which can be implemented with temporary values using Array methods but dealing with async events can become cumbersome.

RxJS simplifies this process by abstracting away the complexity of handling async events, providing a toolkit of operators for transforming and filtering incoming data.

To understand more about Observables and how they handle completion, reading articles like the one by Ben Lesh can be helpful for clarifying concepts and exploring practical examples.

The Power of RxJS

A notable advantage of RxJS lies in its ability to manage asynchronous arrays of events efficiently, eliminating the need to manually track completion state and enabling developers to focus on solving real problems.

Exploring Sync vs. Async Operations

In the realm of Observables, the distinction between synchronous and asynchronous operations depends on the nature of the producer and subscribers. While most observables are designed for handling async scenarios, there are instances where synchronous observables (e.g., Observable.of([1,2,3])) can also be utilized effectively.

Ultimately, the key takeaway is understanding that Observables operate in a lazy/push-based manner, only executing actions when new values are pushed through the operator chain. This push-based model allows for seamless integration of sync and async operations based on the needs of the application.

Comparing synchronous and asynchronous streams in RxJS

Answer №1

The Power of RxJS

Exploring Sync vs. Async Operations

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