Java CopyOnWriteArrayList toArray() 方法

2025年3月21日 | 3 分钟阅读

Java CopyOnWriteArrayList 类的 toArray() 方法返回一个数组，该数组按顺序包含此列表中的所有元素，从第一个到最后一个。toArray() 方法充当基于数组的 API 和基于集合的 API 之间的桥梁。

语法

返回值

此方法返回一个包含此列表中所有元素的数组。

示例 1

import java.util.concurrent.CopyOnWriteArrayList;
import java.util.Arrays;

public class CopyOnWriteArrayListToArrayExample1{
	
	public static void main(String[] args) {
		//Initializing CopyOnWriteArrayList of Integers
		CopyOnWriteArrayList<Integer>numbers = new CopyOnWriteArrayList<>(new Integer[] {1,2,1,4,5,3,3,8});
		Object[] toArrayList = null;
		//Converting list to array list
		toArrayList = numbers.toArray();
		Arrays.toString(toArrayList);
		//Prints Array List
		System.out.println("Array List is : " + Arrays.toString(toArrayList));	
			}
	}

输出

Array List is : [1, 2, 1, 4, 5, 3, 3, 8]

示例 2

import java.util.concurrent.CopyOnWriteArrayList;
import java.util.Arrays;

public class CopyOnWriteArrayListToArrayExample2{
	
	public static void main(String[] args) {
		//Initializing CopyOnWriteArrayList of Integers
		CopyOnWriteArrayList<Integer>numbers = new CopyOnWriteArrayList<>(new Integer[] {});
		Object[] toArrayList = null;
		//Converting list to array list
		toArrayList = numbers.toArray();
		Arrays.toString(toArrayList);
		//Prints Array List
		System.out.println("Array List is : " + Arrays.toString(toArrayList));
			
			}
		}

输出

Array List is : []

示例 3

import java.util.concurrent.CopyOnWriteArrayList;
import java.util.Arrays;

public class CopyOnWriteArrayListToArrayExample3{
	
	public static void main(String[] args) {
		//Initializing CopyOnWriteArrayList of Strings
		CopyOnWriteArrayList<String>listOfNames = new CopyOnWriteArrayList<>(new String[] {"Tom","Harry","John","John","John","Jerry"});
		Object[] toArrayList = null;
		//Converting list to array list
		toArrayList = listOfNames.toArray();
		Arrays.toString(toArrayList);
		//Prints Array List
		System.out.println("Array List is : " + Arrays.toString(toArrayList));
			
			}
		}

输出

Array List is : [Tom, Harry, John, John, John, Jerry]

示例 4

import java.util.concurrent.CopyOnWriteArrayList;
import java.util.Arrays;

public class CopyOnWriteArrayListToArrayExample4{
	
	public static void main(String[] args) {
		//Initializing CopyOnWriteArrayList of Strings
		CopyOnWriteArrayList<String>listOfNames = new CopyOnWriteArrayList<>(new String[] {});
		Object[] toArrayList = null;
		//Converting list to array list
		toArrayList = listOfNames.toArray();
		Arrays.toString(toArrayList);
		//Prints Array List
		System.out.println("Array List is : " + Arrays.toString(toArrayList));		
			}
	}

输出

Array List is : []

Java CopyOnWriteArrayList<E>toArray(T[] a) 方法

Java CopyOnWriteArrayList 类的 toArray(T[] a) 方法返回一个数组，该数组按顺序包含此列表中的所有元素，从第一个到最后一个。返回数组的运行时类型与指定数组的运行时类型相同。

如果列表适合指定数组，则此方法返回其中的数组。否则，将分配一个新数组，其运行时类型与指定数组的运行时类型相同，并且大小与此列表的大小相同。

语法

参数

a - 这是要将列表中的元素存储到的数组。

返回值

此方法返回一个包含此列表中所有元素的数组。

示例 1

import java.util.concurrent.CopyOnWriteArrayList;
import java.util.Arrays;

public class CopyOnWriteArrayListToArrayExample11{
	
	public static void main(String[] args) {
		//Initializing CopyOnWriteArrayList of Integers
		CopyOnWriteArrayList<Integer>numbers = new CopyOnWriteArrayList<>(new Integer[] {1,2,1,4,5,3,3,8});
		Object[] toArrayList = {1,2,10,20,6,6,6,6,6,6,6,6,6,6,6};
		//Converting list to array list
		toArrayList = numbers.toArray(toArrayList);
		Arrays.toString(toArrayList);
		//Prints Array List
		System.out.println("Array List is : " + Arrays.toString(toArrayList));
		
			}
	}

输出

Array List is : [1, 2, 1, 4, 5, 3, 3, 8, null, 6, 6, 6, 6, 6, 6]

示例 2

import java.util.concurrent.CopyOnWriteArrayList;
import java.util.Arrays;

public class CopyOnWriteArrayListToArrayExample12{
	
	public static void main(String[] args) {
		//Initializing CopyOnWriteArrayList of Integers
		CopyOnWriteArrayList<Integer>numbers = new CopyOnWriteArrayList<>(new Integer[] {1,2,1,4,5,3,3,8});
		Object[] toArrayList = {1,2};
		//Converting list to array list
		toArrayList = numbers.toArray(toArrayList);
		Arrays.toString(toArrayList);
		//Prints Array List
		System.out.println("Array List is : " + Arrays.toString(toArrayList));	
				}
		}

输出

Array List is : [1, 2, 1, 4, 5, 3, 3, 8]

示例 3

import java.util.concurrent.CopyOnWriteArrayList;
import java.util.Arrays;

public class CopyOnWriteArrayListToArrayExample13{
	
	public static void main(String[] args) {
		//Initializing CopyOnWriteArrayList of Strings
		CopyOnWriteArrayList<String>listOfNames = new CopyOnWriteArrayList<>(new String[] {"Tom","Harry","John","John","John","Jerry"});
		Object[] toArrayList = {1,2,6,7,6,4,6,6,6,6,6,6,6};
		//Converting list to array list
		toArrayList = listOfNames.toArray(toArrayList);
		Arrays.toString(toArrayList);
		//Prints Array List
		System.out.println("Array List is : " + Arrays.toString(toArrayList));				
			}
		}

输出

Array List is : [Tom, Harry, John, John, John, Jerry, null, 6, 6, 6, 6, 6, 6]

示例 4

import java.util.concurrent.CopyOnWriteArrayList;
import java.util.Arrays;

public class CopyOnWriteArrayListToArrayExample14{
	
	public static void main(String[] args) {
		//Initializing CopyOnWriteArrayList of Strings
		CopyOnWriteArrayList<String>listOfNames = new CopyOnWriteArrayList<>(new String[] {"Tom","Harry","John","John","John","Jerry"});
		Object[] toArrayList = {1,2};
		//Converting list to array list
		toArrayList = listOfNames.toArray(toArrayList);
		Arrays.toString(toArrayList);
		//Prints Array List
		System.out.println("Array List is : " + Arrays.toString(toArrayList));			
			}
	}

输出

Array List is : [Tom, Harry, John, John, John, Jerry]

下一主题Java CopyOnWriteArrayList

我们提供所有技术（如 Java 教程、Android、Java 框架）的教程和面试问题

联系信息

G-13, 2nd Floor, Sec-3, Noida, UP, 201301, India

hr@tpointtech.com

+91-9599086977

关注我们

Python

Java

.Net Framework

AI, ML and Data Science

Cloud Technology

B.Tech and MCA

Web Technology

PHP

Software Testing

Technical Interview

Java Interview

Python

Web Interview

Database Interview

B.Tech / MCA

Important Interview

Software Testing Interview

Company Interviews

Online Compilers

Multiple Choice Questions

Java String 方法

Java 数组类

Java Math 方法

ArrayList 方法

Java List 方法

Java 线程方法

Java Date 类

Java Collection 方法

Java ListIterator 类

Java NIO 教程

HttpURLConnection

Java Deque

Java HttpCookie 类

Java URL 类

Java Vector 类

Java Socket 类

Java Executors

Java Integer 类

Java IdentityHashMap

Java ArrayBlockingQueue

Java Timestamp

Java Spliterator

Java Bitset

Java Instant

Java Compiler 类

Java AtomicInteger 类

Java AtomicLong 方法

Java Authenticator

Java BigDecimal 类

Big Integer 类

Java Boolean 类

Java Byte Class

Java Class

Java Collections 类

CopyOnWriteArrayList

LinkedBlockingDeque

Java Long 类

LinkedTransferQueue

Java List

Java MulticastSocket

Java Number 类

Java Phaser 类

Java CopyOnWriteArrayList toArray() 方法

语法

返回值

示例 1

示例 2

示例 3

示例 4

Java CopyOnWriteArrayList<E>toArray(T[] a) 方法

语法

参数

返回值

示例 1

示例 2

示例 3

示例 4

相关帖子

lastIndexOf()

indexOf()