Java Program to Convert the LinkedList into an Array and vice versa

In this article, we will understand how to convert the linked list into an array and vice versa. The java.util.LinkedList class operations perform we can expect for a doubly-linked list. Operations that index into the list will traverse the list from the beginning or the end, whichever is closer to the specified index.

Below is a demonstration of the same −

Suppose our input is −

The list is defined as: [Java, Python, Scala, Mysql]

The desired output would be −

The result array is: Java Python Scala Mysql

Algorithm

Step 1 - START
Step 2 - Declare namely
Step 3 - Define the values.
Step 4 - Create a list and add elements to it using the ‘add’ method.
Step 5 - Display the list on the console.
Step 6 - Create another empty list of previous list size.
Step 7 - Convert it into array using the ‘toArray’ method.
Step 8 - Iterate over the array and display the elements on the console.
Step 9 - Stop

Example 1

Here, we convert the list to an array.

import java.util.LinkedList;
public class Demo {
   public static void main(String[] args) {
      System.out.println("The required packages have been imported");
      LinkedList<String> input_list= new LinkedList<>();
      input_list.add("Java");
      input_list.add("Python");
      input_list.add("Scala");
      input_list.add("Mysql");
      System.out.println("The list is defined as: " + input_list);
      String[] result_array = new String[input_list.size()];
      input_list.toArray(result_array);
      System.out.print("\nThe result array is: ");
      for(String elements:result_array) {
         System.out.print(elements+" ");
      }
   }
}

Output

The required packages have been imported
The list is defined as: [Java, Python, Scala, Mysql]

The result array is: Java Python Scala Mysql

Example 2

Here, we convert an array to a list.

import java.util.Arrays;
import java.util.LinkedList;
public class Demo {
   public static void main(String[] args) {
      System.out.println("The required packages have been imported");
      String[] result_array = {"Java", "Python", "Scala", "Mysql"};
      System.out.println("The elements of the result_array are defined as: " +
      Arrays.toString(result_array));
      LinkedList<String> result_list= new LinkedList<>(Arrays.asList(result_array));
      System.out.println("\nThe elements of the result list are: " + result_list);
   }
}

Output

The required packages have been imported
The elements of the result_array are defined as: [Java, Python, Scala, Mysql]

The elements of the result list are: [Java, Python, Scala, Mysql]