How do iterators work in different programming languages?

Can you explain how iterators work in Python?

In Python, an iterator is an object that implements the iterator protocol, consisting of the methods iter() and next(). You can create an iterator from a list, for example, using the iter() function.

What about in Java?

In Java, iterators are part of the Java Collections Framework. You can obtain an iterator from a collection using the iterator() method, which allows you to traverse the collection.

How do iterators differ in JavaScript?

In JavaScript, iterators are objects that implement a next() method, returning an object with value and done properties. You can create custom iterators using generator functions.

Can you give an example of a generator in JavaScript?

Sure! Here's a simple generator function:

function* countUpTo(max) {
  let count = 1;
  while (count <= max) {
    yield count;
    count++;
  }
}

You can use it like this:

const counter = countUpTo(5);
console.log(counter.next().value); // 1