Mastering Immutable.js

Replacing collections with new instances

The simplest way to empty a collection is to replace it with a new instance, as shown here:

const empty = (collection) => {  if (collection instanceof List) {    return List();  }  if (collection instanceof Map) {    return Map();  }  return null;};const myList = List.of(1, 2);const myMap = Map.of('one', 1, 'two', 2);const myEmptyList = empty(myList);const myEmptyMap = empty(myMap);console.log('myList', myList.toJS());// -> myList [ 1, 2 ]console.log('myEmptyList', myEmptyList.toJS());// -> myEmptyList []console.log('myMap', myMap.toJS());// -> myMap { one: 1, two: 2 }console.log('myEmptyMap', myEmptyMap.toJS());// -> myEmptyMap {}

We've created a little helper function called empty(). The idea is that it accepts ...