Iterators and iterables
ES6 introduces a new mechanism of iterating over data. Traversing a list of data and doing something with it is a very common operation. ES6 enhances the iteration constructs. There are two primary concepts involved with this change-iterators and iterables.
Iterators
A JavaScript iterator is an object that exposes the next() method. This method returns the next item from the collection in the form of an object that has two properties-done and value. In the following example, we will return an iterator from an array by exposing the next() method:
//Take an array and return an iterator
function iter(array){
var nextId= 0;
return {
next: function() {
if(nextId < array.length) {
return {value: array[nextId++], done: false};
} else {
return {done: true};
}
}
}
}
var it = iter(['Hello', 'Iterators...
