2026
1 featuresThe Iterator.concat() JavaScript method returns an iterator that yields values from a sequence of iterators, exhausting each iterator before moving on to the next.
2025
1 featuresThe Iterator object is an abstract base for objects that implement the iterator protocol. It provides methods common to built-in iterators, such as filter(), find(), map(), and reduce(). You can also use the static method Iterator.from() to convert an existing iterable into an Iterator.
2020
1 featuresAsynchronous iterator objects, such as those returned by promises or generator functions, are iterable with the for await .. of loop.
2018
1 featuresArrays are iterable with the for … of statement and enumerable with the methods entries(), keys(), and values().
2016
1 featuresTyped arrays are iterable with the for … of statement and enumerable with the methods entries(), keys(), and values().
2015
1 featuresThe for...of loop operates on a sequence of values sourced from an iterable object, such as arrays, array-like objects, DOM collections, iterators, generators, and user-defined iterables. All built-in iterators inherit from the Iterator class.
Limited Availability
3 featuresThe includes() method of an Iterator object returns true when an item yielded by the iterator is the same as a given value. It's similar to the includes() method of arrays.
The Iterator.zip() and Iterator.zipKeyed() static methods return new iterators that aggregate items from multiple iterables. You can use them to iterate jointly, to get all of the items at the same position in each iterable.
The join() method of an Iterator object returns a string concatenation of all the iterator's items, separated by commas or a given separator string. It's similar to the join() method of arrays.