What are some examples of custom iterables in JavaScript?

Can you explain what custom iterables are in JavaScript?

Custom iterables in JavaScript are objects that implement the iterable protocol, allowing them to be used in loops like for...of.

How do I create a custom iterable?

To create a custom iterable, you need to define a method called Symbol.iterator that returns an iterator object.

Can you show me a simple example?

Sure! Here's a simple example:

class MyIterable {
  constructor() {
    this.items = [1, 2, 3];
  }
  [Symbol.iterator]() {
    let index = 0;
    return {
      next: () => {
        if (index < this.items.length) {
          return { value: this.items[index++], done: false };
        } else {
          return { done: true };
        }
      }
    };
  }
}

const iterable = new MyIterable();
for (const item of iterable) {
  console.log(item);
}

What are some use cases for custom iterables?

Custom iterables can be useful for creating collections that can be easily traversed, like data structures or APIs that return data in a specific format.