Convert ArrayList to Array

In this post, we will discuss 2 different ways of converting ArrayList to Array in Java.
  1. Conversion using toArray() method
  2. The manual way of Conversion using ArrayList get() method

1. Conversion using toArray() method

toArray() method

toArray() method returns an array containing all of the elements in this list in proper sequence (from first to the last element); the runtime type of the returned array is that of the specified array. 
If the list fits in the specified array, it is returned therein. Otherwise, a new array is allocated with the runtime type of the specified array and the size of this list.
Example: Example of using toArray() method to convert ArrayList to Array in Java.
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

/**
 * This class shows how to convert ArrayList to Array
 * 
 * @author javaguides.net
 *
 */
public class ArrayListToArray {
 public static void main(String[] args) {
  List<String> strList = new ArrayList<>();
  strList.add("abc");
  strList.add("xyz");
  strList.add("pqr");
  strList.add("mno");

  String[] strArr = null;

  strArr = strList.toArray(new String[strList.size()]);
  System.out.println(Arrays.toString(strArr));
 }
}
Output:
[abc, xyz, pqr, mno]

2. The manual way of Conversion using ArrayList get() method

As we know ArrayList class provides get() API to deal with retrieving elements from a list by index. 
Example: Example of a manual way of Conversion using ArrayList get() method
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

/**
 * This class shows how to convert ArrayList to Array
 * 
 * @author javaguides.net
 *
 */
public class ArrayListToArray {
 public static void main(String[] args) {
                /*ArrayList declaration and initialization*/
  List<String> strList = new ArrayList<>();
  strList.add("abc");
  strList.add("xyz");
  strList.add("pqr");
  strList.add("mno");

                /*ArrayList to Array Conversion */
  String[] strArr = new String[strList.size()];

  for (int i = 0; i < strList.size(); i++) {
   strArr[i] = strList.get(i);
  }

  /*Displaying Array elements*/
  System.out.println(Arrays.toString(strArr));
 }
}
Output:
[abc, xyz, pqr, mno]

Related Array Posts

Free Spring Boot Tutorial | Full In-depth Course | Learn Spring Boot in 10 Hours


Watch this course on YouTube at Spring Boot Tutorial | Fee 10 Hours Full Course

Comments