Java program is the conversion between list (ArrayList) and array (Array)

Comprehensive Java Examples

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

Example1Convert 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 running the program, the output is:

[a, b]

In the above program, we have a string list list. To convert the list to an array, we first created a string array array with a size equal to list.size().

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

Example2: 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 running the program, the output is:

[a, b]

In the above program, we have a string array array. To convert the array to a list, we use the Arrays.asList() method and store it in the list list.

Comprehensive Java Examples