PlainArray

java.lang.Object
- ohos.utils.PlainArray<E>

类型参数:

E - Indicates the type of the value to be stored.

所有已实现的接口:

Cloneable
```
public class PlainArray<E>
extends Object
implements Cloneable
```
A basic collection class to store the data structures that use the primitive data type int as the key and any object as the value.
Values in this class are directly stored in arrays, without being wrapped into other types. This simplifies the data storage structure and saves memory. All key-value pairs in this class are sorted in ascending order when they are stored, and the binary search algorithm is used to efficiently search for a specified key. In such data storage structures, keys and values can be iterated over based on indexes. This class implements the Cloneable interface and supports shallow copy of stored values.
Pay attention to the following when using the PlainArray class:
- This class is non-thread safe.
- The stored value cannot be a null object.
- Values are not stored in the same sequence as they are inserted.
从以下版本开始:

1

字段概要

字段
限定符和类型字段说明

static int INVALID_INDEX
Indicates an invalid index used by index-related operations.

字段
限定符和类型	字段	说明
`static int`	`INVALID_INDEX`	Indicates an invalid index used by index-related operations.

构造器概要

构造器
构造器	说明
`PlainArray()`	A constructor used to create a `PlainArray` instance with an initial capacity.
`PlainArray(int capacity)`	A constructor used to create a `PlainArray` instance with a custom initial capacity.

方法概要

所有方法实例方法具体方法
限定符和类型	方法	说明
`void`	`append(int key, E value)`	Appends a key-value pair to `PlainArray`.
`void`	`clear()`	Clears the current `PlainArray` object.
`PlainArray<E>`	`clone()`	Obtains a clone of the current `PlainArray` object.
`boolean`	`contains(int key)`	Checks whether the current `PlainArray` object contains the specified `key`.
`Optional<E>`	`get(int key)`	Queries the value associated with a specified `key`.
`E`	`get(int key, E defaultValue)`	Queries the value associated with the specified `key` with the `defaultValue` parameter passed.
`int`	`indexOfKey(int key)`	Queries the index for a specified `key`.
`int`	`indexOfValue(E value)`	Queries the index for a specified `value`.
`boolean`	`isEmpty()`	Checks whether the current `PlainArray` object is empty.
`int`	`keyAt(int index)`	Queries the key at a specified index.
`int`	`locate(int key)`	Searches for the index of a specified key.
`void`	`put(int key, E value)`	Adds a key-value pair to `PlainArray`.
`Optional<E>`	`remove(int key)`	Removes the key-value pair based on a specified key.
`Optional<E>`	`removeAt(int index)`	Removes the key-value pair at a specified index.
`int`	`removeBatchAt(int index, int batchSize)`	Removes a size of batch key-value pairs from a specified index.
`void`	`setValueAt(int index, E value)`	Update value on specified index.
`int`	`size()`	Obtains the total number of values stored in the current `PlainArray`.
`String`	`toString()`	Obtains the string representation of the `PlainArray` object.
`E`	`valueAt(int index)`	Queries the value at a specified index.

从类继承的方法 java.lang.Object
equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- 字段详细资料
  - INVALID_INDEX
```
public static final int INVALID_INDEX
```
    Indicates an invalid index used by index-related operations.
    
    从以下版本开始:
    
    1
    
    另请参阅:
    
    常量字段值
- 构造器详细资料
  - PlainArray
```
public PlainArray()
```
    A constructor used to create a PlainArray instance with an initial capacity.
    
    从以下版本开始:
    
    1
  - PlainArray
```
public PlainArray(int capacity)
```
    A constructor used to create a PlainArray instance with a custom initial capacity.
    This constructor allows you to customize the initial capacity of the PlainArray object.
    
    参数:
    
    capacity - Indicates the initial capacity to customize for the object.
    
    抛出:
    
    IllegalArgumentException - Throws this exception if the specified capacity is less than or equal to 0.
    
    从以下版本开始:
    
    1
- 方法详细资料
  - clone
```
public PlainArray<E> clone()
```
    Obtains a clone of the current PlainArray object.
    Note that values stored in the array are shallowly copied.
    
    覆盖:
    
    clone 在类中 Object
    
    返回:
    
    Returns a clone of the PlainArray object.
    
    从以下版本开始:
    
    1
    
    另请参阅:
    
    Cloneable
  - locate
```
public int locate(int key)
```
    Searches for the index of a specified key.
    The binary search algorithm is used for searching. If no result is found, a negative value is returned. However, you can invert this negative value to obtain the index where the key should be stored in the array.
    
    参数:
    
    key - Indicates the key to search for.
    
    返回:
    
    Returns the index of the key; returns a negative value if no result is found.
    
    从以下版本开始:
    
    1
  - put
```
public void put(int key,
                E value)
```
    Adds a key-value pair to PlainArray.
    If the specified key already exists, its value will be replaced by value.
    
    参数:
    
    key - Indicates the key to be added.
    
    value - Indicates the value associated with the key.
    
    抛出:
    
    NullPointerException - Throws this exception if value is null.
    
    从以下版本开始:
    
    1
  - setValueAt
```
public void setValueAt(int index,
                       E value)
```
    Update value on specified index.
    
    参数:
    
    index - Indicates the index to insert.
    
    value - Indicates the value associated with the key.
    
    抛出:
    
    IndexOutOfBoundsException - Throws this exception if the specified index is beyond the valid range.
    
    NullPointerException - Throws this exception if the specified value is null.
    
    从以下版本开始:
    
    1
  - append
```
public void append(int key,
                   E value)
```
    Appends a key-value pair to PlainArray.
    If the key to be added is greater than any existing key in the array, this method is more efficient than the put(int,java.lang.Object) method. If the specified key is not the largest one in the array, the put(int,java.lang.Object) method is automatically called to add the key-value pair.
    
    参数:
    
    key - Indicates the key to be added.
    
    value - Indicates the value associated with the key.
    
    抛出:
    
    NullPointerException - Throws this exception if value is null.
    
    从以下版本开始:
    
    1
  - clear
```
public void clear()
```
    Clears the current PlainArray object.
    
    从以下版本开始:
    
    1
  - keyAt
```
public int keyAt(int index)
```
    Queries the key at a specified index.
    
    参数:
    
    index - Indicates the index to query.
    
    返回:
    
    Returns the key of the specified index.
    
    抛出:
    
    IndexOutOfBoundsException - Throws this exception if the specified index is beyond the valid range.
    
    从以下版本开始:
    
    1
  - remove
```
public Optional<E> remove(int key)
```
    Removes the key-value pair based on a specified key.
    
    参数:
    
    key - Indicates the key to remove.
    
    返回:
    
    Returns an Optional object containing the removed value; returns an empty Optional object if key does not exist.
    
    从以下版本开始:
    
    1
  - removeAt
```
public Optional<E> removeAt(int index)
```
    Removes the key-value pair at a specified index.
    
    参数:
    
    index - Indicates the index of the key-value pair to remove.
    
    返回:
    
    Returns an Optional object with the removed value encapsulated.
    
    抛出:
    
    IndexOutOfBoundsException - Throws this exception if the specified index is beyond the valid range.
    
    从以下版本开始:
    
    1
  - removeBatchAt
```
public int removeBatchAt(int index,
                         int batchSize)
```
    Removes a size of batch key-value pairs from a specified index.
    
    参数:
    
    index - Indicates the index of the key-value pair to remove.
    
    batchSize - Indicates the size of batch to remove.
    
    返回:
    
    Returns the total number of removed values.
    
    抛出:
    
    IndexOutOfBoundsException - Throws this exception if the specified index is beyond the valid range.
    
    IllegalArgumentException - Throws this exception if the specified batchSize is smaller than 1.
    
    从以下版本开始:
    
    3
  - get
```
public Optional<E> get(int key)
```
    Queries the value associated with a specified key.
    
    参数:
    
    key - Indicates the key of the value to query.
    
    返回:
    
    Returns an Optional object containing the obtained value; returns an empty Optional object if key does not exist.
    
    从以下版本开始:
    
    1
  - get
```
public E get(int key,
             E defaultValue)
```
    Queries the value associated with the specified key with the defaultValue parameter passed.
    
    参数:
    
    key - Indicates the key of the value to query.
    
    defaultValue - Indicates the default value.
    
    返回:
    
    Returns the value of key; returns defaultValue if the key does not exist.
    
    从以下版本开始:
    
    1
  - valueAt
```
public E valueAt(int index)
```
    Queries the value at a specified index.
    
    参数:
    
    index - Indicates the index for the value to query.
    
    返回:
    
    Returns the value of the specified index.
    
    抛出:
    
    IndexOutOfBoundsException - Throws this exception if the specified index is beyond the valid range.
    
    从以下版本开始:
    
    1
  - indexOfKey
```
public int indexOfKey(int key)
```
    Queries the index for a specified key.
    
    参数:
    
    key - Indicates the key to query.
    
    返回:
    
    Returns the index for the key; returns INVALID_INDEX if the queried key does not exist.
    
    从以下版本开始:
    
    1
  - indexOfValue
```
public int indexOfValue(E value)
```
    Queries the index for a specified value.
    
    参数:
    
    value - Indicates the value to query.
    
    返回:
    
    Returns the index for the value; returns INVALID_INDEX if the queried value does not exist.
    
    抛出:
    
    NullPointerException - Throws this exception if the queried value is null.
    
    从以下版本开始:
    
    1
  - size
```
public int size()
```
    Obtains the total number of values stored in the current PlainArray.
    
    返回:
    
    Returns the total number of stored values.
    
    从以下版本开始:
    
    1
  - isEmpty
```
public boolean isEmpty()
```
    Checks whether the current PlainArray object is empty.
    
    返回:
    
    Returns true if no value is contained; returns false otherwise.
    
    从以下版本开始:
    
    1
  - contains
```
public boolean contains(int key)
```
    Checks whether the current PlainArray object contains the specified key.
    
    参数:
    
    key - Indicates the key to check.
    
    返回:
    
    Returns true if the specified key exists; returns false otherwise.
    
    从以下版本开始:
    
    1
  - toString
```
public String toString()
```
    Obtains the string representation of the PlainArray object.
    The returned string representation is JSON-compliant, and the values in JSON name/value pairs are returned by toString() method of every elements in the PlainArray object
    
    覆盖:
    
    toString 在类中 Object
    
    返回:
    
    Returns the JSON-based string representation of PlainArray.
    
    从以下版本开始:
    
    1

类 PlainArray<E>

字段概要

构造器概要

方法概要

从类继承的方法 java.lang.Object

字段详细资料

INVALID_INDEX

构造器详细资料

PlainArray

PlainArray

方法详细资料

clone

locate

put

setValueAt

append

clear

keyAt

remove

removeAt

removeBatchAt

get

get

valueAt

indexOfKey

indexOfValue

size

isEmpty

contains

toString