[Javascript] Conditionally spread entries to a JavaScript object

In JavaScript, we often end up composing one object out of several other objects. Luckily there's a convenient spread operator which allows us to spread entries from one object to another.

Sometimes we only want to include something in the newly created object if a certain condition is met. In this lesson we are going to learn how to conditionally add entries to a JavaScript object using the spread operator.

const isAdmin = () => true;

const userData = {
  name: "Tomasz",
  surname: "Łakomy"
};

// TODO:
// if user is an admin, add a is_admin: true
// to the object, otherwise don't add anything
const userObject = {
  id: 123,
  ...userData,
  ...(isAdmin() ? { is_admin: true } : {})
};

console.log(userObject);