---
title: Extracting values
description: Leave Result safely with match or a fallback, and understand when unwrap throws.
---

## Prefer `match` at handling boundaries

```ts
const response = result.match({
  ok: (value) => Response.json(value, { status: 200 }),
  err: (error) => toErrorResponse(error),
});
```

Both branches are visible and the output type is unified.

## Provide a fallback with `unwrapOr`

```ts
const port = parsePort(input).unwrapOr(3000);
// number
```

The fallback may have a different type, so the result is the union of the success and fallback types.

Static forms:

```ts
Result.unwrapOr(result, defaultValue);
Result.unwrapOr(defaultValue)(result);
```

## Assert success with `unwrap`

```ts
const value = result.unwrap();
const value = result.unwrap("Configuration must be valid at startup");
```

On `Err`, `unwrap` throws `Panic`; the error value is preserved as its cause. Use this only where an `Err` proves an invariant is broken or where an outer defect boundary intentionally terminates the operation.

## Do not unwrap routine failures

Avoid:

```ts
const user = findUser(id).unwrap(); // missing user is expected
```

Handle or propagate instead:

```ts
const greeting = findUser(id).map((user) => `Hello, ${user.name}`);
```

> **unwrap is an assertion**
>
> `unwrap` is not a substitute for error handling. Its meaning is: “an Err here is a defect.”