# Arn

- Source: [`core/lib/arn.ts`](https://github.com/aws/aws-cdk/blob/v2.275.0/packages/aws-cdk-lib/core/lib/arn.ts#L121)
- Type last changed: v2.2.0 · 15 Dec 2021

## Methods

- `extractResourceName(arn: string, resourceType: string): string` (static) — Extract the full resource name from an ARN.

  Necessary for resource names (paths) that may contain the separator, like
  `arn:aws:iam::111111111111:role/path/to/role/name`.

  Only works if we statically know the expected `resourceType` beforehand, since we're going
  to use that to split the string on ':<resourceType>/' (and take the right-hand side).

  We can't extract the 'resourceType' from the ARN at hand, because CloudFormation Expressions
  only allow literals in the 'separator' argument to `{ Fn::Split }`, and so it can't be
  `{ Fn::Select: [5, { Fn::Split: [':', ARN] }}`.

  Only necessary for ARN formats for which the type-name separator is `/`.

- `format(components: ArnComponents, stack?: Stack): string` (static) — Creates an ARN from components.

  If `partition`, `region` or `account` are not specified, the stack's
  partition, region and account will be used.

  If any component is the empty string, an empty string will be inserted
  into the generated ARN at the location that component corresponds to.

  The ARN will be formatted as follows:

    arn:{partition}:{service}:{region}:{account}:{resource}{sep}{resource-name}

  The required ARN pieces that are omitted will be taken from the stack that
  the 'scope' is attached to. If all ARN pieces are supplied, the supplied scope
  can be 'undefined'.

- `split(arn: string, arnFormat: ArnFormat): ArnComponents` (static) — Splits the provided ARN into its components.

  Works both if 'arn' is a string like 'arn:aws:s3:::bucket',
  and a Token representing a dynamic CloudFormation expression
  (in which case the returned components will also be dynamic CloudFormation expressions,
  encoded as Tokens).

  **Parameters**

  - `arn` — the ARN to split into its components.
  - `arnFormat` — the expected format of 'arn' - depends on what format the service 'arn' represents uses.