Mastering Immutable.js

Strict equality

Strict equality is used when you're looking for a value in a collection, and you have something with which you can compare it. For example, you could define a filter function that uses strict equality to look for values that equal 1 or 2, as follows:

const filter = i => i === 1 || i === 2;

You can then pass this function to the filter() method of a list:

const myList = List.of(1, 2, 3);const myFilteredList = myList.filter(filter);console.log('myList', myList.toJS());// -> myList [ 1, 2, 3 ]console.log('myFilteredList', myFilteredList.toJS());// -> myFilteredList [ 1, 2 ]

You can use the same function to filter maps, as shown here:

const myMap = Map.of(  'one', 1,  'two', 2,  'three', 3);const myFilteredMap = myMap.filter(filter); ...