Mastering Immutable.js

Iterating with for...of loops

Immutable.js collections follow the JavaScript iterable protocol. Any object that follows it can be used in a for...of loop. This includes sequences, as shown here:

const myList = List.of(1, 2, 3);const myMap = Map.of(  'one', 1,  'two', 2,  'three', 3);for (let item of myList.toSeq()) {  console.log('myList', item);  // -> myList 1  // -> myList 2  // -> myList 3}for (let item of myMap.toSeq()) {  console.log('myMap', item);  // -> myMap [ 'one', 1 ]  // -> myMap [ 'two', 2 ]  // -> myMap [ 'three', 3 ]}

Here, we're converting myList and myMap into their respective sequence types using toSeq(). Then, we're iterating over each value inside of a for...of loop. This is a side-effect: we're iterating over a sequence in order ...