# `Sku`

A seller's own stock code: up to 64 characters with no spaces, such as `AB-1234-XL`.

Use it for your own product codes. For a code printed on the packaging, use [`Ean13`](/docs/types/type-ean13.md), [`UpcA`](/docs/types/type-upc-a.md) or [`Isbn`](/docs/types/type-isbn.md). For one physical item, use [`SerialNumber`](/docs/types/type-serial-number.md).

## Shape

One value, held as text in one set form, with no parts: `tshirt/red/M`.

## Example

```jadpo
Sku("AB-1234-XL")
```

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

`text.parse(raw, as: Sku)` reads one from text that comes from outside. Text that isn't one at all fails `malformed`, such as ` AB-1234-XL` or `AB 1234 XL`.

## 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
"AB-1234-XL"
"tshirt/red/M"
```

## Details

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

`Sku` is in the group Commerce and logistics, 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: `AB-1234-XL` and `tshirt/red/M`.

### How it is stored

It is stored in one column named for the field, of type `text`. `tshirt/red/M` is stored as `'tshirt/red/M'`.

### How it is shown to people

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

With `locale: Locale.en_gb`:

| Value | Shown |
|---|---|
| `AB-1234-XL` | `AB-1234-XL` |
| `tshirt/red/M` | `tshirt/red/M` |

### 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>