# `IataAirport`

An airport's three-letter code, as tickets print it: `LHR`.

Use it for flights and passengers. For air traffic control's four-letter code, use [`IcaoAirport`](/docs/types/type-icao-airport.md). For shipping ports, use [`UnLocode`](/docs/types/type-un-locode.md).

## Shape

One value, held as text in one set form, with no parts: `JFK`.

## Example

```jadpo
IataAirport("LHR")
```

`IataAirport(raw)` checks the text, and text that isn't one breaks the `format` rule.

`text.parse(raw, as: IataAirport)` reads one from text that comes from outside. Text that isn't one at all fails `malformed`, such as `lhr`, `LH` or `EGLL`.

## Good to know

- `==` tells you whether two are the same. `<` and `list.sort_by` don't take it.

## In JSON

A string, in a request, a response or `json.write`:

```json
"LHR"
"JFK"
```

## Details

<details>
<summary>Text form, storage, how it is shown, and operations</summary>

`IataAirport` is in the group Travel, and has been in Jadpo since 0.1.0.

### Text form

`text.from` writes one standard text form, the same form `text.parse` reads back: `LHR` and `JFK`.

### How it is stored

It is stored in one column named for the field, of type `text`. `JFK` is stored as `'JFK'`.

### How it is shown to people

`text.format(value, locale:)` shows it to people in their locale.

With `locale: Locale.en_gb`:

| Value | Shown |
|---|---|
| `LHR` | `LHR` |
| `JFK` | `JFK` |

### Operations

It also takes `text.parse`, `text.from`, `text.format`, `json.read`, `json.write` and `==`. [How every standard type behaves](/docs/every-standard-type-meets-one-contract.md) says how they work.

</details>