Logical Operators and Assignment are new features in JavaScript for 2020. These are a suite of new operators which edit a JavaScript object. Their goal is to re-use the concept of mathematical operators (e.g. += -= *=) but with logic instead.

interface User {
  id?: number
  name: string
  location: {
      postalCode?: string
  }
}

function updateUser(user: User) {
  // This code can be replaced 
  if (!user.id) user.id = 1

  // Or this code:
  user.id = user.id || 1

  // With this code:
  user.id ||= 1
}

declare const user: User
user.location.postalCode ||= "90210"