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## Example: combining three or more types

```javascript
let value: string | number | boolean;

value = "Hello";  // string
value = 42;       // number
value = true;     // boolean
value = null;     // Error - null is not part of the union
```

> That is, `value` can be a **string**, a **number**, or a **boolean**,
> but nothing else.

---

## Example with types via `type`

```javascript
type Status = "loading" | "success" | "error" | "idle";

let current: Status;

current = "loading"; // ok
current = "error";   // ok
current = "pending"; // Error - not part of the union
```

> Such string unions are often used for **states, roles, statuses, and modes**.

---

## Example: combining different structures

```javascript
type User = { name: string };
type Admin = { name: string; permissions: string[] };
type Guest = { guestId: number };

type Person = User | Admin | Guest;

const a: Person = { name: "Tim" };                   // User
const b: Person = { name: "Alex", permissions: [] }; // Admin
const c: Person = { guestId: 123 };                  // Guest
```

> `Person` can now represent **any of the three** data shapes.

---

## How many can you combine?

As many as you like.
There is no limit on the number of combined types:

TypeScript handles this without any trouble -
what matters is that the code stays **readable and meaningful**.

---

## Remember

| Property | Description |
|---|---|
| Union operator | ` |
| Number of types | Not limited |
| Purpose | A variable or function can accept **one of the specified values** |
| Common use | Statuses, roles, states, different data variants |

---

**A real-life example:**

```javascript
type PaymentMethod = "cash" | "card" | "apple-pay" | "google-pay" | "paypal";

function pay(method: PaymentMethod) {
  console.log("Payment via:", method);
}

pay("cash");       // ok
pay("paypal");     // ok
pay("bitcoin");    // Error - not part of the union
```

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