# Class: MapObjectType

## MapObjectType(mapSubTypeopt, keyTypeopt, valueTypeopt)

Class representing a map type of Ignite object.

It is described by COMPOSITE_TYPE.MAP ObjectType.COMPOSITE_TYPE and one of MapObjectType.MAP_SUBTYPE.

## Constructor

#### new MapObjectType(mapSubTypeopt, keyTypeopt, valueTypeopt)

Public constructor.

Optionally specifies a kind of map and types of keys and values in the map.

If a kind of map is not specified, MAP_SUBTYPE.HASH_MAP is assumed.

If key and/or value type is not specified then during operations the Ignite client will try to make automatic mapping between JavaScript types and Ignite object types - according to the mapping table defined in the description of the ObjectType class.

##### Parameters:

Name | Type | Attributes | Default | Description
--- | --- | --- | --- | ---
`mapSubType` | MapObjectType.MAP_SUBTYPE | <optional> | MAP_SUBTYPE.HASH_MAP | map subtype, one of the MapObjectType.MAP_SUBTYPE constants.
`keyType` | ObjectType.PRIMITIVE_TYPE | CompositeType | <optional> | null | type of the keys in the map: either a type code of primitive (simple) type or an instance of class representing non-primitive (composite) type or null (or not specified) that means the type is not specified
`valueType` | ObjectType.PRIMITIVE_TYPE | CompositeType | <optional> | null | type of the values in the map: either a type code of primitive (simple) type or an instance of class representing non-primitive (composite) type or null (or not specified) that means the type is not specified

Source:
  - ObjectType.js, line 339

### Extends

- CompositeType

### Members

#### (static, readonly) MAP_SUBTYPE

Supported kinds of map.

##### Properties:

Name | Type | Description
--- | --- | ---
`HASH_MAP` |  | 1
`LINKED_HASH_MAP` |  | 2

Source:
  - ObjectType.js, line 318