The Basics/Utility Classes

There are a handful of utility classes provided with iter-over that come ready-to-use.

EmptyIterator

Want an empty iterator that doesn't return any content? This is the iterator for you!

let empty: EmptyIterator = new EmptyIterator();

empty.hasNext() // 'false'
empty.next() // 'undefined'

Seems useless, but in a way, that's kind of the point. Rarely, it happens to be semantically useful to have an iterator that does nothing.

ObjectIterator

How many times have you typed out the classic for (let prop of Object.keys(myObj)) ... mantra? More than three times? Yeah, me too. Here's an easy way to loop over the key-value pairs present in an object:

let props: ObjectIterator<Person> = new ObjectIterator(jasonBourne);

for (let kvPair of props) console.log(`${kvPair.key}: ${kvPair.value}`);

// 'firstName: Jason'
// 'lastName: Bourne'
// 'middleInitial: F'