# `AbaRoutingNumber`

A US bank's ABA routing number, nine digits with a 3-7-1 checksum: `021000021`.

[Money and banking](types.md#money-and-banking); not ordered; since Jadpo 0.1.0.

## Make one

Build one from its text, `AbaRoutingNumber("011000015")`, which checks it: text that isn't one breaks `format`.

`text.parse(raw, as: AbaRoutingNumber)` reads one from its text; text that isn't one at all fails `malformed`, such as `011000016`, `01100001` or `0110000150`.

## Text, JSON and storage

`text.from` writes its canonical text, the one form `text.parse` reads back. JSON sends its canonical text as a string.

| Text | JSON |
|---|---|
| `011000015` | `"011000015"` |
| `021000021` | `"021000021"` |

It is stored in one column named for the field, of type `text`. `021000021` is stored as `'021000021'`.

## Shown to people

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

With `locale: Locale.en_gb`:

| Value | Shown |
|---|---|
| `011000015` | `011000015` |
| `021000021` | `021000021` |

## Operations

It has the contract's own operations: `text.parse`, `text.from`, `text.format`, `json.read`, `json.write` and `==`. It isn't ordered, so `<` and sorting don't take it. [Every standard type meets one contract](../topics/every-standard-type-meets-one-contract.md) says how they work.