在Java中,我们可以使用将List转换为数组,参考以下步骤:

  • 循环(for / while / do-while)
  • List.toArray()
  • Stream(在Java8中引入)

文件:ListToArrayExample.java -

package com.yiibai.tutorial;

import java.util.ArrayList;
import java.util.List;

/**
 * @author yiibai
 *
 */
public class ListToArrayExample {
    public static void main(String[] args) {
        //List to be converted into array
        List<String> list=new ArrayList<>();
        list.add("A");
        list.add("B");
        list.add("C");
        list.add("D");
        list.add("E");

        /*Method - 1 (Using for loop)*/
        String[] array1=new String[list.size()];
        for (int i = 0; i < list.size(); i++) {
            array1[i]=list.get(i);
        }
        System.out.println("Method -1 Output:");
        for (String string : array1) {
            System.out.println(string);
        }

        /*Method - 2 (List.toArray())*/
        String[] array2=list.toArray(new String[list.size()]);
        System.out.println("
Method -2 Output:");
        for (String string : array2) {
            System.out.println(string);
        }

        /*Method - 3 (Using stream)*/
        String[] array3=list.stream().toArray(String[]::new);
        System.out.println("
Method -3 Output:");
        for (String string : array3) {
            System.out.println(string);
        }
    }
}

执行上面示例代码,得到以下结果 -

Method -1 Output:
A
B
C
D
E

Method -2 Output:
A
B
C
D
E

Method -3 Output:
A
B
C
D
E