Clean Code in JavaScript

Static methods

Static methods and properties can be declared by using the static keyword:

class Accounts {  static allAccounts = [];  static tallyAllAccounts() {    // ...  }}Accounts.tallyAllAccounts();Accounts.allAccounts; // => []

These properties and methods could also easily be added after the initial class definition:

Accounts.countAccounts = () => {  return Accounts.allAccounts.length;};

Static methods are useful when you have a method or property whose functionality and existence are semantically related to the entire class as opposed to a singular instance.