harmony 鸿蒙@ohos.util.PlainArray (Nonlinear Container PlainArray)

  • 2025-06-12
  • 浏览 (5)

@ohos.util.PlainArray (Nonlinear Container PlainArray)

PlainArray stores key-value (KV) pairs. Each key must be unique, be of the number type, and have only one value.

PlainArray is based on generics and uses a lightweight structure. Keys in the array are searched using binary search and are mapped to values in other arrays.

Both PlainArray and LightWeightMap are used to store KV pairs in the lightweight structure. However, the key type of PlainArray can only be number.

Recommended use case: Use PlainArray when you need to store KV pairs whose keys are of the number type.

This topic uses the following to identify the use of generics: - T: Type

NOTE

The initial APIs of this module are supported since API version 8. Newly added APIs will be marked with a superscript to indicate their earliest API version.

Modules to Import

import { PlainArray } from '@kit.ArkTS';

PlainArray

Attributes

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

System capability: SystemCapability.Utils.Lang

Name Type Readable Writable Description
length number Yes No Number of elements in a plain array (called container later).

constructor

constructor()

A constructor used to create a PlainArray instance.

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

System capability: SystemCapability.Utils.Lang

Error codes

For details about the error codes, see Utils Error Codes.

ID Error Message
10200012 The PlainArray’s constructor cannot be directly invoked.

Example

let plainArray: PlainArray<string> = new PlainArray();

isEmpty

isEmpty(): boolean

Checks whether this container is empty.

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

System capability: SystemCapability.Utils.Lang

Return value

Type Description
boolean Returns true if the container is empty; returns false otherwise.

Error codes

For details about the error codes, see Utils Error Codes.

ID Error Message
10200011 The isEmpty method cannot be bound.

Example

const plainArray: PlainArray<string> = new PlainArray();
let result = plainArray.isEmpty();

has

has(key: number): boolean

Checks whether this container contains the specified key.

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
key number Yes Target key. The value must be less than or equal to int32_max, that is, 2147483647.

Return value

Type Description
boolean Returns true if the specified key is contained; returns false otherwise.

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 has method cannot be bound.

Example

let plainArray: PlainArray<string> = new PlainArray();
plainArray.add(1, "squirrel");
let result = plainArray.has(1);

get

get(key: number): T

Obtains the value of the specified key in this container.

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
key number Yes Target key. The value must be less than or equal to int32_max, that is, 2147483647.

Return value

Type Description
T Value of the key.

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 get method cannot be bound.

Example

let plainArray: PlainArray<string> = new PlainArray();
plainArray.add(1, "squirrel");
plainArray.add(2, "sparrow");
let result = plainArray.get(1);

getIndexOfKey

getIndexOfKey(key: number): number

Obtains the index of the element with the specified key in this container.

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
key number Yes Target key. The value must be less than or equal to int32_max, that is, 2147483647.

Return value

Type Description
number Returns the position index if obtained; returns -1 otherwise.

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 getIndexOfKey method cannot be bound.

Example

let plainArray: PlainArray<string> = new PlainArray();
plainArray.add(1, "squirrel");
plainArray.add(2, "sparrow");
let result = plainArray.getIndexOfKey(2);

getIndexOfValue

getIndexOfValue(value: T): number

Obtains the index of the first occurrence of an element with the specified value in this container.

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 T Yes Value of the target element.

Return value

Type Description
number Returns the position index if obtained; returns -1 otherwise.

Error codes

For details about the error codes, see Utils Error Codes.

ID Error Message
10200011 The getIndexOfValue method cannot be bound.

Example

let plainArray: PlainArray<string> = new PlainArray();
plainArray.add(1, "squirrel");
plainArray.add(2, "sparrow");
let result = plainArray.getIndexOfValue("squirrel");

getKeyAt

getKeyAt(index: number): number

Obtains the key of the element at the specified position in this container.

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 Position index of the target element. The value must be less than or equal to int32_max, that is, 2147483647.

Return value

Type Description
number Returns the key of the element if obtained; returns -1 otherwise.

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 getKeyAt method cannot be bound.

Example

let plainArray: PlainArray<string> = new PlainArray();
plainArray.add(1, "squirrel");
plainArray.add(2, "sparrow");
let result = plainArray.getKeyAt(1);

getValueAt

getValueAt(index: number): T

Obtains the value of an element at the specified position in this container.

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 Position index of the target element. The value must be less than or equal to int32_max, that is, 2147483647.

Return value

Type Description
T Returns the value of the element if obtained; returns undefined otherwise.

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.
10200001 The value of index is out of range.
10200011 The getValueAt method cannot be bound.

Example

let plainArray: PlainArray<string> = new PlainArray();
plainArray.add(1, "squirrel");
plainArray.add(2, "sparrow");
let result = plainArray.getValueAt(1);

clone

clone(): PlainArray&lt;T&gt;

Clones this container and returns a copy. The modification to the copy does not affect the original instance.

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

System capability: SystemCapability.Utils.Lang

Return value

Type Description
PlainArray&lt;T&gt; New PlainArray instance obtained.

Error codes

For details about the error codes, see Utils Error Codes.

ID Error Message
10200011 The clone method cannot be bound.

Example

let plainArray: PlainArray<string> = new PlainArray();
plainArray.add(1, "squirrel");
plainArray.add(2, "sparrow");
let newPlainArray = plainArray.clone();

add

add(key: number, value: T): void

Adds an element to this container.

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
key number Yes Key of the target element. The value must be less than or equal to int32_max, that is, 2147483647.
value T Yes Value of the target element.

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 add method cannot be bound.

Example

let plainArray: PlainArray<string> = new PlainArray();
plainArray.add(1, "squirrel");

remove

remove(key: number): T

Removes a key-value pair with the specified key.

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
key number Yes Target key. The value must be less than or equal to int32_max, that is, 2147483647.

Return value

Type Description
T Value in the key-value pair removed.

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 remove method cannot be bound.

Example

let plainArray: PlainArray<string> = new PlainArray();
plainArray.add(1, "squirrel");
plainArray.add(2, "sparrow");
let result = plainArray.remove(2);

removeAt

removeAt(index: number): T

Removes an element at the specified position from this container.

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 Position index of the target element. The value must be less than or equal to int32_max, that is, 2147483647.

Return value

Type Description
T Element removed.

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 removeAt method cannot be bound.

Example

let plainArray: PlainArray<string> = new PlainArray();
plainArray.add(1, "squirrel");
plainArray.add(2, "sparrow");
let result = plainArray.removeAt(1);

removeRangeFrom

removeRangeFrom(index: number, size: number): number

Removes elements in a specified range from this container.

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 Start position of the elements to remove. The value must be less than or equal to int32_max, that is, 2147483647.
size number Yes Number of elements to remove. The value must be less than or equal to int32_max, that is, 2147483647.

Return value

Type Description
number Number of elements removed.

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.
10200001 The value of index is out of range.
10200011 The removeRangeFrom method cannot be bound.

Example

let plainArray: PlainArray<string> = new PlainArray();
plainArray.add(1, "squirrel");
plainArray.add(2, "sparrow");
let result = plainArray.removeRangeFrom(1, 3);

setValueAt

setValueAt(index: number, value: T): void

Sets a value for an element at the specified position in this container.

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 Position index of the target element. The value must be less than or equal to int32_max, that is, 2147483647.
value T Yes Value of the target element.

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.
10200001 The value of index is out of range.
10200011 The setValueAt method cannot be bound.

Example

let plainArray: PlainArray<string|number> = new PlainArray();
plainArray.add(1, "squirrel");
plainArray.add(2, "sparrow");
plainArray.setValueAt(1, 3546);

toString

toString(): String

Obtains a string that contains all elements in this container.

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

System capability: SystemCapability.Utils.Lang

Return value

Type Description
String String obtained.

Error codes

For details about the error codes, see Utils Error Codes.

ID Error Message
10200011 The toString method cannot be bound.

Example

let plainArray: PlainArray<string> = new PlainArray();
plainArray.add(1, "squirrel");
plainArray.add(2, "sparrow");
let result = plainArray.toString();

clear

clear(): void

Clears this container and sets its length to 0.

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

System capability: SystemCapability.Utils.Lang

Error codes

For details about the error codes, see Utils Error Codes.

ID Error Message
10200011 The clear method cannot be bound.

Example

let plainArray: PlainArray<string> = new PlainArray();
plainArray.add(1, "squirrel");
plainArray.add(2, "sparrow");
plainArray.clear();

forEach

forEach(callbackFn: (value: T, index?: number, PlainArray?: PlainArray&lt;T&gt;) => void, thisArg?: Object): void

Uses a callback to traverse the elements in this container and obtain their position indexes.

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 function Yes Callback invoked to traverse the elements in the container.
thisArg Object No Value of this to use when callbackFn is invoked. The default value is this instance.

callbackFn |Name|Type|Mandatory|Description| |——–|——–|——–|——–| |value|T|Yes|Value of the element that is currently traversed.| |index|number|No|Position index of the element that is currently traversed. The default value is 0.| |PlainArray|PlainArray&lt;T&gt;|No|Instance that calls the forEach API. The default value is this instance.|

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 forEach method cannot be bound.

Example

let plainArray: PlainArray<string> = new PlainArray();
plainArray.add(1, "squirrel");
plainArray.add(2, "sparrow");
plainArray.forEach((value: string, index?: number) => {
  console.log("value:" + value, "index:" + index);
});

// You are not advised to use the add, remove, or removeAt APIs in forEach because they may cause unpredictable risks such as infinite loops. You can use the for loop when inserting or deleting data.
let plainArray: PlainArray<string> = new PlainArray();
for(let i = 0;i < 10;i++) {
  plainArray.add(i,"123");
}

for(let i = 0;i < 10;i++) {
  plainArray.remove(i);
}

[Symbol.iterator]

[Symbol.iterator](): IterableIterator&lt;[number, T]&gt;

Obtains an iterator object that contains key-value pairs, where the key is of the number type.

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&lt;[number, T]&gt; 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 plainArray: PlainArray<string> = new PlainArray();
plainArray.add(1, "squirrel");
plainArray.add(2, "sparrow");

let iter = plainArray[Symbol.iterator]();
let temp: IteratorResult<Object[]> = iter.next();
while(!temp.done) {
  console.log("key:" + temp.value[0]);
  console.log("value:" + temp.value[1]);
  temp = iter.next();
}

// You are not advised to use the add, remove, or removeAt APIs in Symbol.iterator because they may cause unpredictable risks such as infinite loops. You can use the for loop when inserting or deleting data.
let plainArray: PlainArray<string> = new PlainArray();
for(let i = 0;i < 10;i++) {
  plainArray.add(i,"123");
}

for(let i = 0;i < 10;i++) {
  plainArray.remove(i);
}

你可能感兴趣的鸿蒙文章

harmony 鸿蒙ArkTS

harmony 鸿蒙Compilation Toolchain Error Codes

harmony 鸿蒙TypeScript Compiler Error Codes

harmony 鸿蒙Utils Error Codes

harmony 鸿蒙js-apis-arkts-collections

harmony 鸿蒙@arkts.math.Decimal (High-Precision Math Library Decimal)

harmony 鸿蒙@arkts.lang (ArkTS Base Capability)

harmony 鸿蒙@arkts.utils (ArkTS Utils)

harmony 鸿蒙@ohos.util.ArrayList (Linear Container ArrayList)

harmony 鸿蒙@ohos.buffer (Buffer)

0  赞
  • 所属分类： 后端技术
  • 本文标签：
  • 版权声明： 原创文章如转载，请注明本文链接: https://m.seaxiang.com/blog/O1PJQU
热门推荐
标签云
Linux Java Spring Spring Boot docker 大数据 前端 生活 maven golang 软件 spring cloud fintech mac vscode 其他 区块链 以太坊 V神 开发者 技术 股票 git greenplum 分布式事务 chrome mysql flink kafka 设计模式 原理 鸿蒙 seo
最新文章
本文目录