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interface CreateUserRequest {
  username: string;
  age: number;
  email: string;
}

interface UpdateUserRequest {
  username?: string;
  age?: number;
  email?: string;

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interface User {
  username: string;
  age: number;
  email: string;
}

const createUser = (user: User) => {
  //fetch request that requires all User properties
}

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interface User {
  id: string;
  updated_at: string;
  username: string;
  age: number;
  email: string;
}

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type UserForm = Omit<User, 'id' | 'updated_at'>;

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let name = "Bob"
let age = 24
name = age //hey you mutated the name variable!

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state = {
  name: "Bob",
  age: 24,
  hobbies: ["swimming", "hiking"],
  background: {
    jobs: ["mechanic", "bank teller"],
  },
}

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state.hobbies.push("reading")

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const initialFormState = {
  email: "",
  password: "",
  valid: false,
}

function Form() {
  const [form, setForm] = useState(initialFormState)

  //when updating the password field

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const [users, setUsers] = useState([
  { id: 1, name: "Bob", age: 24, emailConfirmed: false },
  { id: 2, name: "Sarah", age: 30, emailConfirmed: true },
  { id: 3, name: "Kevin", age: 20, emailConfirmed: false },
])

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//confirmedUserId derived from email confirmation
setUsers(prevState => prevState.map(user => (user.id === confirmedUserId ? { ...user, emailConfirmed: true } : user)))