Asynchronous Loops in JavaScript

Asynchronous Loops in JavaScript

How can we iterate over an array asynchronously in JavaScript? Is it even possible?

Let's begin with the simplest method: using a for loop while calling await for asynchronous operations. Here's an example:

const callback = async (item, index, arr) => {
  // Async operation
};

const array = [1, 2, 3];
for (let i = 0; i < array.length; i++) {
  await callback(array[i], i, array);
}

This method is straightforward to implement. However, what are the drawbacks of this approach? The main concern is usability; we are all accustomed to using .map(), .forEach(), and other methods built into Array.prototype.

So, are there other ways to iterate through a loop? Yes, we can use recursion. In this method, each iteration is processed through a separate callback. Here's an example:

const iterate = async (index, array) => {
  // Await an operation
  if (index !== array.length - 1) {
    await iterate(index + 1, array);
  }
};

This recursive method offers no advantages over a for loop, but it is a valid implementation.

For years, I have relied on the first method across various projects. To simplify my work, I decided to create a small, publicly accessible library that can be utilized with any framework. Thus, I developed the library available at: 🔗 waitEach.

This library is easy to include and offers two methods: install and waitEach.

• The first method extends Array.prototype by adding a new method, .waitEach, which functions similarly to .map(), .forEach(), and other native methods, providing a more convenient API.
• The second method allows you to execute waitEach without extending Array.prototype.

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I encourage you to try it out!

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