# argument-declaration Schema

```txt
https://amazonalexa.com/ask/2020/12/ArgumentsDeclaration#/items
```

The representation of an argument declaration.

| Abstract            | Extensible | Status         | Identifiable | Custom Properties | Additional Properties | Access Restrictions | Defined In                                                                                    |
| :------------------ | :--------- | :------------- | :----------- | :---------------- | :-------------------- | :------------------ | :-------------------------------------------------------------------------------------------- |
| Can be instantiated | No         | Unknown status | No           | Forbidden         | Forbidden             | none                | [ArgumentsDeclaration.json\*](../../schemas/ArgumentsDeclaration.json "open original schema") |

## items Type

`object` ([argument-declaration](argumentsdeclaration-argument-declaration.md))

# items Properties

| Property                                | Type     | Required | Nullable       | Defined by                                                                                                                                                                                       |
| :-------------------------------------- | :------- | :------- | :------------- | :----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| [name](#name)                           | `string` | Required | cannot be null | [ArgumentsDeclaration](genericargumentsdeclaration-items-properties-name.md "https://amazonalexa.com/ask/2020/12/Name#/items/properties/name")                                                   |
| [type](#type)                           | `object` | Required | cannot be null | [ArgumentsDeclaration](actiondeclaration-properties-typereference.md "https://amazonalexa.com/ask/2020/12/TypeReference#/items/properties/type")                                                 |
| [defaultExpression](#defaultexpression) | Merged   | Optional | cannot be null | [ArgumentsDeclaration](argumentsdeclaration-argument-declaration-properties-defaultexpression.md "https://amazonalexa.com/ask/2020/12/ArgumentsDeclaration#/items/properties/defaultExpression") |
| [annotations](#annotations)             | `array`  | Optional | cannot be null | [ArgumentsDeclaration](argumentsdeclaration-argument-declaration-properties-annotations.md "https://amazonalexa.com/ask/2020/12/ArgumentsDeclaration#/items/properties/annotations")             |

## name

A name.

`name`

*   is required

*   Type: `string` ([Name](genericargumentsdeclaration-items-properties-name.md))

*   cannot be null

*   defined in: [ArgumentsDeclaration](genericargumentsdeclaration-items-properties-name.md "https://amazonalexa.com/ask/2020/12/Name#/items/properties/name")

### name Type

`string` ([Name](genericargumentsdeclaration-items-properties-name.md))

### name Constraints

**pattern**: the string must match the following regular expression: 

```regexp
^[a-zA-Z_][a-zA-Z0-9_]*$
```

[try pattern](https://regexr.com/?expression=%5E%5Ba-zA-Z_%5D%5Ba-zA-Z0-9_%5D*%24 "try regular expression with regexr.com")

### name Examples

```json
"foo"
```

```json
"bar"
```

```json
"person"
```

```json
"foo1"
```

## type

The representation of a reference to a type declaration.

`type`

*   is required

*   Type: `object` ([TypeReference](actiondeclaration-properties-typereference.md))

*   cannot be null

*   defined in: [ArgumentsDeclaration](actiondeclaration-properties-typereference.md "https://amazonalexa.com/ask/2020/12/TypeReference#/items/properties/type")

### type Type

`object` ([TypeReference](actiondeclaration-properties-typereference.md))

## defaultExpression

Indicates whether the argument is required. If the argument is not provided in an 'Call' expression, this expression will be used instead.

`defaultExpression`

*   is optional

*   Type: merged type ([Details](argumentsdeclaration-argument-declaration-properties-defaultexpression.md))

*   cannot be null

*   defined in: [ArgumentsDeclaration](argumentsdeclaration-argument-declaration-properties-defaultexpression.md "https://amazonalexa.com/ask/2020/12/ArgumentsDeclaration#/items/properties/defaultExpression")

### defaultExpression Type

merged type ([Details](argumentsdeclaration-argument-declaration-properties-defaultexpression.md))

one (and only one) of

*   [Call](actiondeclaration-properties-annotations-call.md "check type definition")

*   [property reference](arguments-definitions-arg-expression-oneof-property-reference.md "check type definition")

*   [name](arguments-definitions-arg-expression-oneof-name.md "check type definition")

## annotations



`annotations`

*   is optional

*   Type: `object[]` ([Call](actiondeclaration-properties-annotations-call.md))

*   cannot be null

*   defined in: [ArgumentsDeclaration](argumentsdeclaration-argument-declaration-properties-annotations.md "https://amazonalexa.com/ask/2020/12/ArgumentsDeclaration#/items/properties/annotations")

### annotations Type

`object[]` ([Call](actiondeclaration-properties-annotations-call.md))