Types

NOTE

The initial APIs of this module are supported since API version 12. Newly added APIs will be marked with a superscript to indicate their earliest API version.

This module can be imported only to ArkTS files (with the file name extension .ets).

ISendable

type ISendable = lang.ISendable

ISendable is the parent type of all sendable types except null and undefined. It does not have any necessary methods or properties.

Atomic service API: This API can be used in atomic services since API version 12.

System capability: SystemCapability.Utils.Lang

Type	Description
lang.ISendable	Parent type of all sendable types.

ArrayFromMapFn¹⁸⁺

type ArrayFromMapFn<FromElementType, ToElementType> = (value: FromElementType, index: number) => ToElementType

Defines the ArkTS Array reduction function, which is used by the from API of the Array class.

System capability: SystemCapability.Utils.Lang

Atomic service API: This API can be used in atomic services since API version 18.

Parameters

Name	Type	Mandatory	Description
value	FromElementType	Yes	Element that is being processed.
index	number	Yes	Index of the element in the ArkTS array.

Return value

Type	Description
ToElementType	Result of the reduction function, which is used as a new element in the array.

ArrayPredicateFn¹⁸⁺

type ArrayPredicateFn<ElementType, ArrayType> = (value: ElementType, index: number, array: ArrayType) => boolean

Defines the ArkTS Array reduction function, which is used by the some and every APIs of the Array class to determine whether array elements meet certain test conditions.

System capability: SystemCapability.Utils.Lang

Atomic service API: This API can be used in atomic services since API version 18.

Parameters

Name	Type	Mandatory	Description
value	ElementType	Yes	Element that is being processed.
index	number	Yes	Index of the element in the ArkTS array.
array	ArrayType	Yes	ArkTS array that is being traversed.

Return value

Type	Description
boolean	Result of the reduction function, indicating whether the current element meets the test condition. The value true means that the current element or a previous element meets the condition, and false means that no element meets the condition.

ArrayReduceCallback¹⁸⁺

type ArrayReduceCallback<AccType, ElementType, ArrayType> = (previousValue: AccType, currentValue: ElementType, currentIndex: number, array: ArrayType) => AccType

Defines the ArkTS Array reduction function, which is used by the reduceRight API of the Array class.

System capability: SystemCapability.Utils.Lang

Atomic service API: This API can be used in atomic services since API version 18.

Parameters

Name	Type	Mandatory	Description
previousValue	AccType	Yes	Accumulated value of the current traversal.
currentValue	ElementType	Yes	Element that is being traversed in the ArkTS array.
currentIndex	number	Yes	Index of the element in the ArkTS array.
array	ArrayType	Yes	ArkTS array that is being traversed.

Return value

Type	Description
AccType	Result of the reduction function, which is used as the previousValue parameter in the next call of ArrayReduceCallback.

TypedArrayFromMapFn

type TypedArrayFromMapFn<FromElementType, ToElementType> = (value: FromElementType, index: number) => ToElementType

Describes the mapping function of the ArkTS TypedArray.

System capability: SystemCapability.Utils.Lang

Atomic service API: This API can be used in atomic services since API version 12.

Parameters

Name	Type	Mandatory	Description
value	FromElementType	Yes	Element that is currently traversed and used to construct an ArkTS TypedArray.
index	number	Yes	Index of the element, beginning at 0.

Return value

Type	Description
ToElementType	Element value after the mapping.

TypedArrayPredicateFn

type TypedArrayPredicateFn<ElementType, ArrayType> = (value: ElementType, index: number, array: ArrayType) => boolean

Describes the assertion function of the ArkTS TypedArray.

System capability: SystemCapability.Utils.Lang

Atomic service API: This API can be used in atomic services since API version 12.

Parameters

Name	Type	Mandatory	Description
value	ElementType	Yes	Element that is being traversed in the ArkTS TypedArray.
index	number	Yes	Index of the element, beginning at 0.
array	ArrayType	Yes	ArkTS TypedArray that is being traversed.

Return value

Type	Description
boolean	Operation result. The value true is returned if the value meets the condition; otherwise, false is returned.

TypedArrayForEachCallback

type TypedArrayForEachCallback<ElementType, ArrayType> = (value: ElementType, index: number, array: ArrayType) => void

Describes the traversal function of the ArkTS TypedArray.

System capability: SystemCapability.Utils.Lang

Atomic service API: This API can be used in atomic services since API version 12.

Parameters

Name	Type	Mandatory	Description
value	ElementType	No	Element that is being traversed in the ArkTS TypedArray.
index	number	No	Index of the element, beginning at 0.
array	ArrayType	No	ArkTS TypedArray that is being traversed.

TypedArrayMapCallback

type TypedArrayMapCallback<ElementType, ArrayType> = (value: ElementType, index: number, array: ArrayType) => ElementType

Describes the conversion mapping function of the ArkTS TypedArray.

System capability: SystemCapability.Utils.Lang

Atomic service API: This API can be used in atomic services since API version 12.

Parameters

Name	Type	Mandatory	Description
value	ElementType	Yes	Element that is being mapped in the ArkTS TypedArray.
index	number	Yes	Index of the element, beginning from 0.
array	ArrayType	Yes	ArkTS TypedArray that is being mapped.

Return value

Type	Description
ElementType	Element value after the mapping.

TypedArrayReduceCallback

type TypedArrayReduceCallback<AccType, ElementType, ArrayType> = (previousValue: AccType, currentValue: ElementType, currentIndex: number, array: ArrayType) => AccType

Describes the reduce function of the ArkTS TypedArray.

System capability: SystemCapability.Utils.Lang

Atomic service API: This API can be used in atomic services since API version 12.

Parameters

Name	Type	Mandatory	Description
previousValue	AccType	Yes	Accumulated value of the current traversal.
currentValue	ElementType	Yes	Element that is being traversed in the ArkTS TypedArray.
currentIndex	number	Yes	Index of the element, beginning at 0.
array	ArrayType	Yes	ArkTS TypedArray that is being traversed.

Return value

Type	Description
AccType	Result of the reduce function. The result is passed in to the previousValue parameter when TypedArrayReduceCallback is called next time.

TypedArrayCompareFn

type TypedArrayCompareFn<ElementType> = (first: ElementType, second: ElementType) => number

Describes the sort function of the ArkTS TypedArray.

System capability: SystemCapability.Utils.Lang

Atomic service API: This API can be used in atomic services since API version 12.

Parameters

Name	Type	Mandatory	Description
first	ElementType	Yes	First element to be compared.
second	ElementType	Yes	Second element to be compared.

Return value

Type	Description
number	Comparison result of the elements. If `first` is less than `second`, the return value is a negative number. If `first` is greater than `second`, the return value is a positive number. If `first` is equal to `second`, the return value is 0.