Java Program to Convert List (ArrayList) to Array and Vice-Versa

In this program, you'll learn to convert a list to an array using toArray() and array to list using asList() in Java.

Example 1: Convert list to array

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

public class ListArray {

    public static void main(String[] args) {

        List<String> list = new ArrayList<String>();
        list.add("a");
        list.add("b");

        String[] array = new String[list.size()];
        list.toArray(array);

        System.out.println(Arrays.toString(array));

    }
}

When you run the program, the output will be:

[a, b]

In the above program, we've an list of strings list. To convert the list to an array, first we created a string array named array with size equals to list.size().

Then, we simply used list's toArray() method to convert the list items to array items.


Example 2: Convert Array to list

import java.util.Arrays;
import java.util.List;

public class ArrayToList {

    public static void main(String[] args) {

        String[] array = {"a", "b"};
        List<String> list = Arrays.asList(array);

        System.out.println(list);

    }
}

When you run the program, the output will be:

[a, b]

In the above program, we've an array of strings array. To convert the array to a list, we used Arrays's asList() method and stored it in the list, list.