Mastering Immutable.js

Iterating with forEach()

As an alternative to for...of loops, the forEach() method can be used by sequences to execute side-effects, as follows:

const myList = List.of(1, 2, 3);const myMap = Map.of(  'one', 1,  'two', 2,  'three', 3);myList  .toSeq()  .forEach(item => console.log('myList', item));  // -> myList 1  // -> myList 2  // -> myList 3myMap  .toSeq()  .forEach(item => console.log('myMap', item));  // -> myMap 1  // -> myMap 2  // -> myMap 3

Using this approach, we end up with the same result as using for...of loops to execute our side-effects. The toSeq() call isn't necessary in order to use forEach(); however, the advantage that it has over for...of loops is that it's a chainable method that can be attached to your sequence transformations. ...