Class (Float32Array)
A linear data structure that is implemented on ArkTS ArrayBuffer.
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).
Decorator: @Sendable
Modules to Import
import { collections } from '@kit.ArkTS';
Properties
System capability: SystemCapability.Utils.Lang
Atomic service API: This API can be used in atomic services since API version 12.
| Name | Type | Read Only | Optional | Description |
|---|---|---|---|---|
| buffer | ArrayBuffer | Yes | No | Bottom-layer buffer used by an ArkTS Float32Array. |
| byteLength | number | Yes | No | Number of bytes occupied by an ArkTS Float32Array. |
| byteOffset | number | Yes | No | Offset between the ArkTS Float32Array and the start position of the ArrayBuffer. |
| length | number | Yes | No | Number of elements in an ArkTS Float32Array. |
| BYTES_PER_ELEMENT | number | Yes | No | Number of bytes occupied by each element in the ArkTS Float32Array. |
constructor
constructor()
A constructor used to create an empty ArkTS Float32Array.
System capability: SystemCapability.Utils.Lang
Atomic service API: This API can be used in atomic services since API version 12.
Error codes
For details about the error codes, see Utils Error Codes.
| ID | Error Message |
|---|---|
| 10200012 | The Float32Array's constructor cannot be directly invoked. |
Example
let float32Array: collections.Float32Array = new collections.Float32Array();
constructor
constructor(length: number)
A constructor used to create an ArkTS Float32Array of a given length.
Atomic service API: This API can be used in atomic services since API version 12.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| length | number | Yes | Length of the ArkTS Float32Array. |
Error codes
For details about the error codes, see Universal Error Codes and Utils Error Codes.
| ID | Error Message |
|---|---|
| 401 | Parameter error. |
| 10200012 | The Float32Array's constructor cannot be directly invoked. |
Example
// Construct an object with the length parameter.
let float32Array: collections.Float32Array = new collections.Float32Array(12);
constructor
constructor(elements: Iterable<number>)
A constructor that creates an ArkTS Float32Array from an iterable object.
Atomic service API: This API can be used in atomic services since API version 12.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| elements | Iterable<number> | Yes | An iterable collection of numbers used to construct an ArkTS Float32Array object. |
Error codes
For details about the error codes, see Universal Error Codes and Utils Error Codes.
| ID | Error Message |
|---|---|
| 401 | Parameter error. |
| 10200012 | The Float32Array's constructor cannot be directly invoked. |
Example
// Construct objects from an iterable object.
let set: Set<number> = new Set<number>([1, 2, 3]);
let array: collections.Float32Array = new collections.Float32Array(set);
// Float32Array [1, 2, 3]
constructor
constructor(array: ArrayLike<number>|ArrayBuffer)
A constructor that creates an ArkTS Float32Array from an array-like object or ArkTS ArrayBuffer.
Atomic service API: This API can be used in atomic services since API version 12.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| array | ArrayLike<number> |ArrayBuffer | Yes | Object used to construct the ArkTS Float32Array. When the parameter type is ArrayBuffer, the number of bytes occupied by the buffer must be an integer multiple of 4. |
Error codes
For details about the error codes, see Universal Error Codes and Utils Error Codes.
| ID | Error Message |
|---|---|
| 401 | Parameter error. |
| 10200012 | The Float32Array's constructor cannot be directly invoked. |
Example
// Example 1: Construct an object from an array-like object.
let arrayLike = [1, 3, 5];
let array: collections.Float32Array = new collections.Float32Array(arrayLike);
// Example 2: Construct an object from an ArrayBuffer.
let arrayBuffer: collections.ArrayBuffer = new collections.ArrayBuffer(12);
let array: collections.Float32Array = new collections.Float32Array(arrayBuffer);
// Example 3: Construct an object from another ArkTS Float32Array.
let arrayLike = [1, 3, 5];
// float32Array1 [1, 3, 5]
let float32Array1: collections.Float32Array = new collections.Float32Array(arrayLike);
// float32Array2 [1, 3, 5]
let float32Array2: collections.Float32Array = new collections.Float32Array(float32Array1);
constructor
constructor(buffer: ArrayBuffer, byteOffset?: number, length?: number)
A constructor that creates an ArkTS Float32Array from an ArrayBuffer.
Atomic service API: This API can be used in atomic services since API version 12.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| buffer | ArrayBuffer | Yes | ArrayBuffer object used to construct the ArkTS Float32Array. The number of bytes occupied by the buffer must be an integer multiple of 4. |
| byteOffset | number | No | Byte offset of the buffer, beginning at 0. The default value is 0. |
| length | number | No | Length of the ArkTS Float32Array. The default value is 0. |
Error codes
For details about the error codes, see Universal Error Codes and Utils Error Codes.
| ID | Error Message |
|---|---|
| 401 | Parameter error. |
| 10200012 | The Float32Array's constructor cannot be directly invoked. |
Example
let float32Array: collections.Float32Array = collections.Float32Array.from([1, 2, 3, 4, 5, 6]);
console.info("byteLength: " + float32Array.buffer.byteLength); // byteLength: 24
// Start from the fourth byte of the buffer corresponding to Float32Array. The length is 5.
let float32Array1: collections.Float32Array = new collections.Float32Array(float32Array.buffer, 4, 5);
console.info("[" + float32Array1 + "]"); // [2, 3, 4, 5, 6]
from
static from(arrayLike: ArrayLike<number>): Float32Array
Creates an ArkTS Float32Array from an array-like or iterator object.
Atomic service API: This API can be used in atomic services since API version 12.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| arrayLike | ArrayLike<number> | Yes | Array-like object used to construct the ArkTS Float32Array. |
Return value
| Type | Description |
|---|---|
| Float32Array | New ArkTS Float32Array generated. |
Error codes
For details about the error codes, see Universal Error Codes.
| ID | Error Message |
|---|---|
| 401 | Parameter error. |
Example
let arrayLike = [1, 3, 5];
let array: collections.Float32Array = collections.Float32Array.from(arrayLike); // array [1, 3, 5]
from
static from<T>(arrayLike: ArrayLike<T>, mapFn: TypedArrayFromMapFn<T, number>): Float32Array
Creates an ArkTS Float32Array from an array-like object.
Atomic service API: This API can be used in atomic services since API version 12.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| arrayLike | ArrayLike<T> | Yes | Array-like object used to construct the ArkTS Float32Array. |
| mapFn | TypedArrayFromMapFn<T, number> | Yes | Mapping function. |
Return value
| Type | Description |
|---|---|
| Float32Array | New ArkTS Float32Array generated. |
Error codes
For details about the error codes, see Universal Error Codes.
| ID | Error Message |
|---|---|
| 401 | Parameter error. |
Example
// Example 1: Create an ArkTS Float32Array from an object.
let array: collections.Float32Array = collections.Float32Array.from<number>(
{ length: 5 }, (v: Object, k: number) => k);
// Float32Array [0, 1, 2, 3, 4]
// Example 2: Create an ArkTS Float32Array from a string array.
let array: collections.Float32Array = collections.Float32Array.from<string>(
["1", "3", "5"], (v: string, k: number) => parseInt(v));
// Float32Array [1, 3, 5]
// Example 3: Create an ArkTS Float32Array from a string.
let array: collections.Float32Array = collections.Float32Array.from<string>(
"12345", (v: string, k: number) => parseInt(v));
// Float32Array [1, 2, 3, 4, 5]
from
static from(arrayLike: Iterable<number>, mapFn?: TypedArrayFromMapFn<number, number>): Float32Array
Creates an ArkTS Float32Array from an iterator object.
Atomic service API: This API can be used in atomic services since API version 12.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| arrayLike | Iterable<number> | Yes | Iterator object used to construct the ArkTS Float32Array. |
| mapFn | TypedArrayFromMapFn<number, number> | No | Mapping function. If no value is passed in, no special processing is conducted on the elements. |
Return value
| Type | Description |
|---|---|
| Float32Array | New ArkTS Float32Array generated. |
Error codes
For details about the error codes, see Universal Error Codes.
| ID | Error Message |
|---|---|
| 401 | Parameter error. |
Example
// Example 1: No mapping function is specified.
let set: Set<number> = new Set<number>([1, 2, 3]);
let array: collections.Float32Array = collections.Float32Array.from(set);
// Float32Array [1, 2, 3]
// Example 2: A mapping function is specified.
let set: Set<number> = new Set<number>([1, 2, 3]);
let array: collections.Float32Array = collections.Float32Array.from(
set, (v: number, k: number) => v + k);
// Float32Array [1, 3, 5]
of18+
static of(...items: number[]): Float32Array
Creates an ArkTS Float32Array with a variable number of parameters.
Atomic service API: This API can be used in atomic services since API version 18.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| items | number[] | No | Array of elements used to create the array. The number of elements can be zero, one, or more. |
Return value
| Type | Description |
|---|---|
| Float32Array | New ArkTS Float32Array instance. |
Error codes
For details about the error codes, see Universal Error Codes.
| ID | Error Message |
|---|---|
| 401 | Parameter error: Possible causes: 1. Mandatory parameters are left unspecified;2. Incorrect parameter types;3. Parameter verification failed. |
Example
let arr: collections.Float32Array = collections.Float32Array.of(1, 2, 3, 4);
console.info(arr.toString()); // Expected output: 1,2,3,4
toString18+
toString(): string
Converts an ArkTS Float32Array into a string.
Atomic service API: This API can be used in atomic services since API version 18.
System capability: SystemCapability.Utils.Lang
Return value
| Type | Description |
|---|---|
| string | A string that contains all elements of the array. |
Error codes
For details about the error codes, see Utils Error Codes.
| ID | Error Message |
|---|---|
| 10200011 | The toString method cannot be bound. |
| 10200201 | Concurrent modification error. |
Example
let array = new collections.Float32Array([1, 2, 3, 4, 5]);
let stringArray = array.toString();
console.info(stringArray); // Expected output: 1,2,3,4,5
toLocaleString18+
toLocaleString(): string
Generates a string of digits that matches the cultural conventions of the current system locale. Each element converts its digits to a string via its toLocaleString API, and these strings are then joined in sequence with commas (,).
Atomic service API: This API can be used in atomic services since API version 18.
System capability: SystemCapability.Utils.Lang
Return value
| Type | Description |
|---|---|
| string | A string that contains all elements of the array. |
Error codes
For details about the error codes, see Utils Error Codes.
| ID | Error Message |
|---|---|
| 10200011 | The toLocaleString method cannot be bound. |
| 10200201 | Concurrent modification error. |
Example
// The system where the application is running is set to the French locale.
let array = new collections.Float32Array([1000, 2000, 3000]);
let stringArray = array.toLocaleString();
console.info(stringArray); // Expected output: 1,000, 2,000, 3,000
copyWithin
copyWithin(target: number, start: number, end?: number): Float32Array
Copies elements within a given range from this ArkTS Float32Array to another position in sequence.
Atomic service API: This API can be used in atomic services since API version 12.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| target | number | Yes | Start index of the range. If a negative number is passed in, it refers to the index of target + array.length. |
| start | number | Yes | Start index of the range. If a negative number is passed in, it refers to the index of start + Float32Array.length. |
| end | number | No | End index of the range (exclusive). If a negative number is passed in, it refers to the index of end + Float32Array.length. The default value is the length of the ArkTS Float32Array. |
Return value
| Type | Description |
|---|---|
| Float32Array | ArkTS Float32Array after being modified. |
Error codes
For details about the error codes, see Universal Error Codes and Utils Error Codes.
| ID | Error Message |
|---|---|
| 401 | Parameter error. |
| 10200011 | The copyWithin method cannot be bound. |
| 10200201 | Concurrent modification error. |
Example
let array: collections.Float32Array = collections.Float32Array.from([1, 2, 3, 4, 5, 6, 7, 8]);
let copied: collections.Float32Array = array.copyWithin(3, 1, 3);
// Float32Array [1, 2, 3, 2, 3, 6, 7, 8]
some
some(predicate: TypedArrayPredicateFn<number, Float32Array>): boolean
Checks whether any element in this ArkTS Float32Array meets a given condition.
Atomic service API: This API can be used in atomic services since API version 12.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| predicate | TypedArrayPredicateFn<number, Float32Array> | Yes | Assertion function used for the test. |
Return value
| Type | Description |
|---|---|
| boolean | Check result. The value true is returned if an element meeting the given condition exists; otherwise, false is returned. |
Error codes
For details about the error codes, see Universal Error Codes and Utils Error Codes.
| ID | Error Message |
|---|---|
| 401 | Parameter error. |
| 10200011 | The some method cannot be bound. |
| 10200201 | Concurrent modification error. |
Example
let arrayLike = [-10, 20, -30, 40, -50];
let float32Array: collections.Float32Array = new collections.Float32Array(arrayLike);
float32Array.some((element: number) => element < 0); // true
every
every(predicate: TypedArrayPredicateFn<number, Float32Array>): boolean
Checks whether all elements in this ArkTS Float32Array meet a given condition.
Atomic service API: This API can be used in atomic services since API version 12.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| predicate | TypedArrayPredicateFn<number, Float32Array> | Yes | Assertion function used for the test. |
Return value
| Type | Description |
|---|---|
| boolean | Check result. The value true is returned if all elements meet the given condition; otherwise, false is returned. |
Error codes
For details about the error codes, see Universal Error Codes and Utils Error Codes.
| ID | Error Message |
|---|---|
| 401 | Parameter error. |
| 10200011 | The every method cannot be bound. |
| 10200201 | Concurrent modification error. |
Example
let arrayLike = [-10, 20, -30, 40, -50];
let float32Array: collections.Float32Array = new collections.Float32Array(arrayLike);
float32Array.every((element: number) => element > 0); // false
fill
fill(value: number, start?: number, end?: number): Float32Array
Fills all elements in a given range in this ArkTS Float32Array with a value.
Atomic service API: This API can be used in atomic services since API version 12.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| value | number | Yes | Value to fill in. |
| start | number | No | Start index of the range. If a negative number is passed in, it refers to the index of start + Float32Array.length. The default value is 0. |
| end | number | No | End index of the range (exclusive). If a negative number is passed in, it refers to the index of end + Float32Array.length. The default value is the length of the ArkTS Float32Array. |
Return value
| Type | Description |
|---|---|
| Float32Array | Filled ArkTS Float32Array. |
Error codes
For details about the error codes, see Universal Error Codes and Utils Error Codes.
| ID | Error Message |
|---|---|
| 401 | Parameter error. |
| 10200011 | The fill method cannot be bound. |
| 10200201 | Concurrent modification error. |
Example
let arrayLike = [1, 2, 3];
new collections.Float32Array(arrayLike).fill(4); // Float32Array [4, 4, 4]
new collections.Float32Array(arrayLike).fill(4, 1); // Float32Array [1, 4, 4]
new collections.Float32Array(arrayLike).fill(4, 1, 2); // Float32Array [1, 4, 3]
filter
filter(predicate: TypedArrayPredicateFn<number, Float32Array>): Float32Array
Returns a new ArkTS Float32Array that contains all elements that meet the given condition.
Atomic service API: This API can be used in atomic services since API version 12.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| predicate | TypedArrayPredicateFn<number, Float32Array> | Yes | Assertion function used for the test. |
Return value
| Type | Description |
|---|---|
| Float32Array | Filtered ArkTS Float32Array. |
Error codes
For details about the error codes, see Universal Error Codes and Utils Error Codes.
| ID | Error Message |
|---|---|
| 401 | Parameter error. |
| 10200011 | The filter method cannot be bound. |
| 10200201 | Concurrent modification error. |
Example
let array: collections.Float32Array = collections.Float32Array.from([0, 1, 2, 3, 4]);
let filtered: collections.Float32Array = array.filter((element: number) => element % 2 == 0);
// Float32Array [0, 2, 4]
find
find(predicate: TypedArrayPredicateFn<number, Float32Array>): number|undefined
Returns the value of the first element that passes a test provided by a callback function. If none of the elements pass the test, undefined is returned.
Atomic service API: This API can be used in atomic services since API version 12.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| predicate | TypedArrayPredicateFn<number, Float32Array> | Yes | Assertion function used for the test. |
Return value
| Type | Description |
|---|---|
| number |undefined | Value of the first element that passes the test. If none of the elements pass the test, undefined is returned. |
Error codes
For details about the error codes, see Universal Error Codes and Utils Error Codes.
| ID | Error Message |
|---|---|
| 401 | Parameter error. |
| 10200011 | The find method cannot be bound. |
| 10200201 | Concurrent modification error. |
Example
let array: collections.Float32Array = collections.Float32Array.from([0, 1, 2, 3, 4]);
array.find((element: number) => element > 2); // 3
array.find((element: number) => element > 4); // undefined
findIndex
findIndex(predicate: TypedArrayPredicateFn<number, Float32Array>): number
Returns the index of the first element that passes a test provided by a callback function. If none of the elements pass the test, -1 is returned.
Atomic service API: This API can be used in atomic services since API version 12.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| predicate | TypedArrayPredicateFn<number, Float32Array> | Yes | Assertion function used for the test. |
Return value
| Type | Description |
|---|---|
| number | Index of the first element that passes the test. If none of the elements pass the test, -1 is returned. |
Error codes
For details about the error codes, see Universal Error Codes and Utils Error Codes.
| ID | Error Message |
|---|---|
| 401 | Parameter error. |
| 10200011 | The findIndex method cannot be bound. |
| 10200201 | Concurrent modification error. |
Example
const array: collections.Float32Array = collections.Float32Array.from([1, 2, 3, 4, 5]);
let foundIndex: number = array.findIndex((element: number) => element % 2 === 0); // 1
forEach
forEach(callbackFn: TypedArrayForEachCallback<number, Float32Array>): void
Calls a callback function for each element in this ArkTS Float32Array.
Atomic service API: This API can be used in atomic services since API version 12.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| callbackFn | TypedArrayForEachCallback<number, Float32Array> | Yes | Callback function to run for each element. |
Error codes
For details about the error codes, see Universal Error Codes and Utils Error Codes.
| ID | Error Message |
|---|---|
| 401 | Parameter error. |
| 10200011 | The forEach method cannot be bound. |
| 10200201 | Concurrent modification error. |
Example
let float32Array: collections.Float32Array = collections.Float32Array.from([1, 2, 3]);
float32Array.forEach((value: number, index: number, array: collections.Float32Array) => {
console.info(`Element ${value} at index ${index}`);
});
indexOf
indexOf(searchElement: number, fromIndex?: number): number
Returns the index of the first occurrence of a value in this ArkTS Float32Array. If the value is not found, -1 is returned.
Atomic service API: This API can be used in atomic services since API version 12.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| searchElement | number | Yes | Value to search for. |
| fromIndex | number | No | Index from which the search starts. The default value is 0. If the index is greater than or equal to the length of the ArkTS Float32Array, -1 is returned. If a negative number is passed in, the search starts from the end of the ArkTS Float32Array. |
Return value
| Type | Description |
|---|---|
| number | Index of the first occurrence of the value. If the value is not found, -1 is returned. |
Error codes
For details about the error codes, see Universal Error Codes and Utils Error Codes.
| ID | Error Message |
|---|---|
| 401 | Parameter error. |
| 10200011 | The indexOf method cannot be bound. |
| 10200201 | Concurrent modification error. |
Example
let array: collections.Float32Array = collections.Float32Array.from([3, 5, 9]);
array.indexOf(3); // 0
array.indexOf(7); // -1
array.indexOf(9, 2); // 2
array.indexOf(9, -2); // 2
lastIndexOf18+
lastIndexOf(searchElement: number, fromIndex?: number): number
Obtains the index of the last occurrence of the specified value in this ArkTS Float32Array.
Atomic service API: This API can be used in atomic services since API version 18.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| searchElement | number | Yes | Value to search for. |
| fromIndex | number | No | Index from which the search starts. The default value is 0. If the index is greater than or equal to the length of the ArkTS Float32Array, -1 is returned. If a negative number is passed in, the search starts from the end of the ArkTS Float32Array. |
Return value
| Type | Description |
|---|---|
| number | Index of the last occurrence of the value. If the value is not found, -1 is returned. |
Error codes
For details about the error codes, see Utils Error Codes.
| ID | Error Message |
|---|---|
| 10200011 | The lastIndexOf method cannot be bound. |
| 10200201 | Concurrent modification error. |
Example
let array: collections.Float32Array = collections.Float32Array.from([3, 5, 9]);
console.info(array.lastIndexOf(3) + ''); // Expected output: 0
console.info(array.lastIndexOf(7) + ''); // Expected output: -1
console.info(array.lastIndexOf(9, 2) + ''); // Expected output: 2
console.info(array.lastIndexOf(9, -2) + ''); // Expected output: -1
join
join(separator?: string): string
Concatenates all elements in this ArkTS Float32Array into a string, with a given separator.
Atomic service API: This API can be used in atomic services since API version 12.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| separator | string | No | Separator to be used. If no value is passed in, a comma (,) is used as the separator. |
Return value
| Type | Description |
|---|---|
| string | String obtained. If the array is empty, an empty string is returned. |
Error codes
For details about the error codes, see Universal Error Codes and Utils Error Codes.
| ID | Error Message |
|---|---|
| 401 | Parameter error. |
| 10200011 | The join method cannot be bound. |
| 10200201 | Concurrent modification error. |
Example
let array: collections.Float32Array = collections.Float32Array.from([1, 2, 3, 4, 5]);
let joined: string = array.join('-'); // "1-2-3-4-5"
map
map(callbackFn: TypedArrayMapCallback<number, Float32Array>): Float32Array
Applies a callback function to each element in this ArkTS Float32Array and uses the result to create an ArkTS Float32Array.
Atomic service API: This API can be used in atomic services since API version 12.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| callbackFn | TypedArrayMapCallback<number, Float32Array> | Yes | Callback function to run for each element. |
Return value
| Type | Description |
|---|---|
| Float32Array | New ArkTS Float32Array. |
Error codes
For details about the error codes, see Universal Error Codes and Utils Error Codes.
| ID | Error Message |
|---|---|
| 401 | Parameter error. |
| 10200011 | The map method cannot be bound. |
| 10200201 | Concurrent modification error. |
Example
let array: collections.Float32Array = collections.Float32Array.from([25, 36, 49]);
const mapped: collections.Float32Array = array.map(Math.sqrt); // Float32Array [5, 6 ,7]
reduce
reduce(callbackFn: TypedArrayReduceCallback<number, number, Float32Array>): number
Applies a reduce function on each element in this ArkTS Float32Array and returns the final reduction result.
Atomic service API: This API can be used in atomic services since API version 12.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| callbackFn | TypedArrayReduceCallback<number, number, Float32Array> | Yes | Reduce function. |
Return value
| Type | Description |
|---|---|
| number | Final result obtained from the last call of the reduce function. |
Error codes
For details about the error codes, see Universal Error Codes and Utils Error Codes.
| ID | Error Message |
|---|---|
| 401 | Parameter error. |
| 10200011 | The reduce method cannot be bound. |
| 10200201 | Concurrent modification error. |
Example
let array: collections.Float32Array = collections.Float32Array.from([1, 2, 3, 4, 5]);
let reducedValue: number = array.reduce((accumulator: number, value: number) => accumulator + value);
// reducedValue == 15
reduceRight18+
reduceRight(callbackFn: TypedArrayReduceCallback<number, number, Float32Array>): number
Reversely traverses this ArkTS Float32Array, applies a reduce function on each element in the array, and returns the final reduction result.
Atomic service API: This API can be used in atomic services since API version 18.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| callbackFn | TypedArrayReduceCallback<number, number, Float32Array> | Yes | Reduce function. |
Return value
| Type | Description |
|---|---|
| number | Final result obtained from the last call of the reduce function. |
Error codes
For details about the error codes, see Universal Error Codes and Utils Error Codes.
| ID | Error Message |
|---|---|
| 401 | Parameter error. Possible causes: 1.Mandatory parameters are left unspecified. 2.Incorrect parameter types. |
| 10200011 | The reduceRight method cannot be bound. |
| 10200201 | Concurrent modification error. |
Example
let array: collections.Float32Array = collections.Float32Array.from([1, 2, 3, 4, 5]);
let reducedValue: number = array.reduceRight((accumulator: number, value: number) => accumulator + value);
console.info(reducedValue + ''); // Expected output: 15
reduce
reduce<U = number>(callbackFn: TypedArrayReduceCallback<U, number, Float32Array>, initialValue: U): U
Applies a reduce function for each element in this ArkTS Float32Array, receives an initial value as the parameter called by the reduce function for the first time, and returns the final reduction result.
Atomic service API: This API can be used in atomic services since API version 12.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| callbackFn | TypedArrayReduceCallback<U, number, Float32Array> | Yes | Reduce function. |
| initialValue | U | Yes | Initial value. |
Return value
| Type | Description |
|---|---|
| U | Final result obtained from the last call of the reduce function. |
Error codes
For details about the error codes, see Universal Error Codes and Utils Error Codes.
| ID | Error Message |
|---|---|
| 401 | Parameter error. |
| 10200011 | The reduce method cannot be bound. |
| 10200201 | Concurrent modification error. |
Example
let array: collections.Float32Array = collections.Float32Array.from([1, 2, 3, 4, 5]);
let reducedValue: number = array.reduce((accumulator: number, value: number) => accumulator + value, 1);
// reducedValue == 16
reduceRight18+
reduceRight<U = number>(callbackFn: TypedArrayReduceCallback<U, number, Float32Array>, initialValue: U): U
Reversely traverses this ArkTS Float32Array, applies a reduce function for each element in the array, receives an initial value as the parameter called by the reduce function for the first time, and returns the final reduction result.
Atomic service API: This API can be used in atomic services since API version 18.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| callbackFn | TypedArrayReduceCallback<U, number, Float32Array> | Yes | Reduce function. |
| initialValue | U | Yes | Initial value. |
Return value
| Type | Description |
|---|---|
| U | Final result obtained from the last call of the reduce function. |
Error codes
For details about the error codes, see Universal Error Codes and Utils Error Codes.
| ID | Error Message |
|---|---|
| 401 | Parameter error. Possible causes: 1.Mandatory parameters are left unspecified. 2.Incorrect parameter types. |
| 10200011 | The reduceRight method cannot be bound. |
| 10200201 | Concurrent modification error. |
Example
let array: collections.Float32Array = collections.Float32Array.from([1, 2, 3, 4, 5]);
let reducedValue: number = array.reduceRight((accumulator: number, value: number) => accumulator + value, 1);
console.info(reducedValue + ''); // Expected output: 16
reverse
reverse(): Float32Array
Reverses this ArkTS Float32Array.
Atomic service API: This API can be used in atomic services since API version 12.
System capability: SystemCapability.Utils.Lang
Return value
| Type | Description |
|---|---|
| Float32Array | Reversed ArkTS Float32Array. |
Error codes
For details about the error codes, see Utils Error Codes.
| ID | Error Message |
|---|---|
| 10200011 | The reverse method cannot be bound. |
| 10200201 | Concurrent modification error. |
Example
let array: collections.Float32Array = collections.Float32Array.from([1, 2, 3, 4, 5]);
let reversed: collections.Float32Array = array.reverse(); // Float32Array [5, 4, 3, 2, 1]
set
set(array: ArrayLike<number>, offset?: number): void
Writes the elements in an array-like object to the given start position in sequence.
Atomic service API: This API can be used in atomic services since API version 12.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| array | ArrayLike<number> | Yes | Array-like object whose elements will be written. |
| offset | number | No | Start position for writing data. The default value is 0. |
Error codes
For details about the error codes, see Universal Error Codes and Utils Error Codes.
| ID | Error Message |
|---|---|
| 401 | Parameter error. |
| 10200011 | The set method cannot be bound. |
| 10200201 | Concurrent modification error. |
Example
let buffer: collections.ArrayBuffer = new collections.ArrayBuffer(32);
let array: collections.Float32Array = new collections.Float32Array(buffer);
array.set([1, 2, 3], 3); // Float32Array [0, 0, 0, 1, 2, 3, 0, 0]
slice
slice(start?: number, end?: number): Float32Array
Selects a range of elements in this ArkTS Float32Array to create an ArkTS Float32Array.
Atomic service API: This API can be used in atomic services since API version 12.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| start | number | No | Start index of the range. If a negative number is passed in, it refers to the index of start + Float32Array.length. The default value is 0. |
| end | number | No | End index of the range (exclusive). If a negative number is passed in, it refers to the index of end + Float32Array.length. The default value is the length of the ArkTS Float32Array. |
Return value
| Type | Description |
|---|---|
| Float32Array | New ArkTS Float32Array. |
Error codes
For details about the error codes, see Universal Error Codes and Utils Error Codes.
| ID | Error Message |
|---|---|
| 401 | Parameter error. |
| 10200011 | The slice method cannot be bound. |
| 10200201 | Concurrent modification error. |
Example
let array: collections.Float32Array = collections.Float32Array.from([1, 2, 3, 4, 5]);
array.slice(); // Float32Array [1, 2, 3, 4, 5]
array.slice(1, 3); // Float32Array [2, 3]
array.slice(-2); // Float32Array [4, 5]
sort
sort(compareFn?: TypedArrayCompareFn<number>): Float32Array
Sorts elements in this ArkTS Float32Array and returns the sorted ArkTS Float32Array.
Atomic service API: This API can be used in atomic services since API version 12.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| compareFn | TypedArrayCompareFn<number> | No | Function that determines the sort order. By default, elements are sorted in ascending order. |
Return value
| Type | Description |
|---|---|
| Float32Array | Sorted ArkTS Float32Array. |
Error codes
For details about the error codes, see Universal Error Codes and Utils Error Codes.
| ID | Error Message |
|---|---|
| 401 | Parameter error. |
| 10200011 | The sort method cannot be bound. |
| 10200201 | Concurrent modification error. |
Example
let array: collections.Float32Array = collections.Float32Array.from([1, 3, 5, 4, 2]);
array.sort(); // Float32Array [1, 2, 3, 4, 5]
array.sort((a: number, b: number) => a - b); // Float32Array [1, 2, 3, 4, 5]
array.sort((a: number, b: number) => b - a); // Float32Array [5, 4, 3, 2, 1]
subarray
subarray(begin?: number, end?: number): Float32Array
Truncates an array from a specified position and returns a new ArkTS Float32Array based on the same ArkTS ArrayBuffer.
Atomic service API: This API can be used in atomic services since API version 12.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| begin | number | No | Start index of the range. If a negative number is passed in, it refers to the index of begin + Float32Array.length. The default value is 0. |
| end | number | No | End index of the range (exclusive). If a negative number is passed in, it refers to the index of end + Float32Array.length. The default value is the length of the ArkTS Float32Array. |
Return value
| Type | Description |
|---|---|
| Float32Array | New ArkTS Float32Array. |
Error codes
For details about the error codes, see Universal Error Codes and Utils Error Codes.
| ID | Error Message |
|---|---|
| 401 | Parameter error. |
| 10200011 | The subarray method cannot be bound. |
| 10200201 | Concurrent modification error. |
Example
let array: collections.Float32Array = collections.Float32Array.from([1, 2, 3, 4, 5]);
let subArray: collections.Float32Array = array.subarray(); // Float32Array [1, 2, 3, 4, 5]
subArray.set([10, 20, 30]); // Float32Array [10, 20, 30, 4, 5]
at
at(index: number): number|undefined
Returns the element at the given index. If no element is found, undefined is returned.
Atomic service API: This API can be used in atomic services since API version 12.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| index | number | Yes | Index of the element. The index in an array always starts from 0 and is an integer. If a negative number is passed in, it refers to the index of index + Float32Array.length. |
Return value
| Type | Description |
|---|---|
| number |undefined | Element obtained. If no element is found, undefined is returned. |
Error codes
For details about the error codes, see Universal Error Codes and Utils Error Codes.
| ID | Error Message |
|---|---|
| 401 | Parameter error. |
| 10200011 | The at method cannot be bound. |
| 10200201 | Concurrent modification error. |
Example
let array: collections.Float32Array = collections.Float32Array.from([1, 2, 3, 4, 5]);
console.info("element: " + array.at(2)); // element: 3
console.info("element: " + array.at(-1)); // element: 5
console.info("element: " + array.at(6)); // element: undefined
includes
includes(searchElement: number, fromIndex?: number): boolean
Checks whether elements are contained in this ArkTS Float32Array.
Atomic service API: This API can be used in atomic services since API version 12.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| searchElement | number | Yes | Element to search for. |
| fromIndex | number | No | Index from which the search starts. If a negative number is passed in, it refers to the index of fromIndex + Float32Array.length. The default value is 0. |
Return value
| Type | Description |
|---|---|
| boolean | Check result. The value true is returned if the element exists; otherwise, false is returned. |
Error codes
For details about the error codes, see Universal Error Codes and Utils Error Codes.
| ID | Error Message |
|---|---|
| 401 | Parameter error. |
| 10200011 | The includes method cannot be bound. |
| 10200201 | Concurrent modification error. |
Example
let array: collections.Float32Array = collections.Float32Array.from([1, 2, 3]);
console.info("includes: " + array.includes(2)); // includes: true
console.info("includes: " + array.includes(4)); // includes: false
console.info("includes: " + array.includes(3, 3)); // includes: false
entries
entries(): IterableIterator<[number, number]>
Returns an iterator object that contains the key-value pair of each element in this ArkTS Float32Array.
Atomic service API: This API can be used in atomic services since API version 12.
System capability: SystemCapability.Utils.Lang
Return value
| Type | Description |
|---|---|
| IterableIterator<[number, number]> | Iterator object. |
Error codes
For details about the error codes, see Utils Error Codes.
| ID | Error Message |
|---|---|
| 10200011 | The entries method cannot be bound. |
| 10200201 | Concurrent modification error. |
Example
let array: collections.Float32Array = collections.Float32Array.from([11, 22, 33]);
let iterator: IterableIterator<[number, number]> = array.entries();
console.info("value: " + iterator.next().value); // value: 0,11
console.info("value: " + iterator.next().value); // value: 1,22
console.info("value: " + iterator.next().value); // value: 2,33
keys
keys(): IterableIterator<number>
Returns an iterator object that contains the key (index) of each element in this ArkTS Float32Array.
Atomic service API: This API can be used in atomic services since API version 12.
System capability: SystemCapability.Utils.Lang
Return value
| Type | Description |
|---|---|
| IterableIterator<number> | Iterator object. |
Error codes
For details about the error codes, see Utils Error Codes.
| ID | Error Message |
|---|---|
| 10200011 | The keys method cannot be bound. |
| 10200201 | Concurrent modification error. |
Example
let array: collections.Float32Array = collections.Float32Array.from([1, 2, 3, 4, 5]);
let iterator: IterableIterator<number> = array.keys();
for (const key of iterator) {
console.info("" + key); // 0, 1, 2, 3, and 4 are returned in sequence.
}
values
values(): IterableIterator<number>
Returns an iterator object that contains the value of each element in this ArkTS Float32Array.
Atomic service API: This API can be used in atomic services since API version 12.
System capability: SystemCapability.Utils.Lang
Return value
| Type | Description |
|---|---|
| IterableIterator<number> | Iterator object. |
Error codes
For details about the error codes, see Utils Error Codes.
| ID | Error Message |
|---|---|
| 10200011 | The values method cannot be bound. |
| 10200201 | Concurrent modification error. |
Example
let array: collections.Float32Array = collections.Float32Array.from([1, 2, 3, 4, 5]);
let iterator: IterableIterator<number> = array.values();
for (const value of iterator) {
console.info("" + value); // 1, 2, 3, 4, and 5 are returned in sequence.
}
[Symbol.iterator]
[Symbol.iterator](): IterableIterator<number>
Returns an iterator, each item of which is a JavaScript object.
NOTE
This API cannot be used in .ets files.
Atomic service API: This API can be used in atomic services since API version 12.
System capability: SystemCapability.Utils.Lang
Return value
| Type | Description |
|---|---|
| IterableIterator<number> | Iterator obtained. |
Error codes
For details about the error codes, see Utils Error Codes.
| ID | Error Message |
|---|---|
| 10200011 | The Symbol.iterator method cannot be bound. |
Example
let float32Array: collections.Float32Array = collections.Float32Array.from([1, 2, 3, 4, 5, 6]);
for (let item of float32Array) {
console.info(`value : ${item}`);
}
[index: number]
[index: number]: number
Returns the element at a given index in this Float32Array.
Atomic service API: This API can be used in atomic services since API version 12.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| index | number | Yes | Index of the element. The index starts from zero. |
Return value
| Type | Description |
|---|---|
| number | Number data type. |
Example
let float32Array = collections.Float32Array.from([1, 2, 4]);
console.info("Element at index 1: ", float32Array[1]);
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