Java Program to Convert a List to Array and Vice Versa

Example 1: Convert the Java List into Array

 import java.util.ArrayList; class Main { public static void main(String[] args) { ArrayList languages = new ArrayList<>(); // Add elements in the list languages.add("Java"); languages.add("Python"); languages.add("JavaScript"); System.out.println("ArrayList: " + languages); // Create a new array of String type String[] arr = new String[languages.size()]; // Convert ArrayList into the string array languages.toArray(arr); System.out.print("Array: "); for(String item:arr) { System.out.print(item+", "); } } }

Output

 List: [Java, Python, JavaScript] Array: Java, Python, JavaScript,

In the above example, we have created an list named languages. Here, we have used the ArrayList class to implement the List.

Notice the line,

 languages.toArray(arr);

Here, the toArray() method converts the list languages into an array. And stores it in the string array arr.

Note: If we don't pass any argument to the toArray() method, the method returns an array of the Object type.

Example 2: Convert Java Array to List

 import java.util.Arrays; import java.util.ArrayList; import java.util.List; class Main { public static void main(String[] args) { // create an array String[] array = {"Java", "Python", "C"}; System.out.println("Array: " + Arrays.toString(array)); // convert array to list List languages= new ArrayList<>(Arrays.asList(array)); System.out.println("List: " + languages); } }

Output

 Array: [Java, Python, C] List: [Java, Python, C]

In the above example, we have created an array of String type. Notice the expression,

 Arrays.asList(array)

Here, the asList() method of the Arrays class converts the specified array into a list.