What is the Iterable Protocol in TypeScript?

Can you explain what the Iterable Protocol is in TypeScript?

The Iterable Protocol in TypeScript allows objects to be iterated over using constructs like for...of. It requires the implementation of a Symbol.iterator method.

How do I implement the Iterable Protocol in my own class?

To implement the Iterable Protocol, define a Symbol.iterator method in your class that returns an iterator object with a next method.

Can you show me a code example of this?

Sure! Here's a simple example:

class MyIterable {
    private items: number[];

    constructor(items: number[]) {
        this.items = items;
    }

    [Symbol.iterator]() {
        let index = 0;
        const items = this.items;
        return {
            next(): IteratorResult<number> {
                if (index < items.length) {
                    return { value: items[index++], done: false };
                } else {
                    return { value: undefined, done: true };
                }
            }
        };
    }
}

const iterable = new MyIterable([1, 2, 3]);
for (const item of iterable) {
    console.log(item);
}

What are some use cases for the Iterable Protocol?

Use cases include creating custom data structures, enabling for...of loops, and integrating with other iterable-based APIs.