The toArray() method of ArrayList is used to return an array containing all the elements in ArrayList in the correct order.
Declaring toArray() method
public Object[] toArray()
or
public <T> T[] toArray(T[] a)
Parameters: This method either accepts no parameters or it takes an array T[] as a parameter which is the array into which the elements of the list are to be stored if it is big enough; otherwise, a new array of the same runtime type is allocated for this purpose.
Return Value: The function returns an array containing all the elements in this list.
Exception: The first overload of this method throws no exceptions. However, the second overload throws the following exceptions:
- ArrayStoreException: if the runtime type of the specified array is not a supertype of the runtime type of every element in this list.
- NullPointerException if the specified array is null
Examples of Java ArrayList.toArray() method
Example 1
Java
// Java Program to illustrate the// ArrayList toArray() method in Javaimport java.util.*;public class GFG { public static void main(String[] args) { // create object of ArrayList ArrayList<Integer> ArrLis = new ArrayList<Integer>(); // Add elements ArrLis.add(32); ArrLis.add(67); ArrLis.add(98); ArrLis.add(100); // print ArrayList System.out.println("ArrayList: " + ArrLis); // Get the array of the elements // of the ArrayList // using toArray() method Object[] arr = ArrLis.toArray(); System.out.println("Elements of ArrayList" + " as Array: " + Arrays.toString(arr)); }} |
Output
ArrayList: [32, 67, 98, 100] Elements of ArrayList as Array: [32, 67, 98, 100]
Example 2
Java
// Java Program to illustrate the// ArrayList toArray(T[]) method in Javaimport java.util.*;// Driver Classpublic class GFG { // main function public static void main(String[] args) { // create object of ArrayList ArrayList<Integer> ArrLis = new ArrayList<Integer>(); // Add elements ArrLis.add(32); ArrLis.add(67); ArrLis.add(98); ArrLis.add(100); // print ArrayList System.out.println(" ArrayList: " + ArrLis); // Get the array of the elements // of the ArrayList // using toArray(T[]) method Integer arr[] = new Integer[ArrLis.size()]; arr = ArrLis.toArray(arr); System.out.println(" Elements of ArrayList " + "as Array: " + Arrays.toString(arr)); }} |
Output
ArrayList: [32, 67, 98, 100] Elements of ArrayList as Array: [32, 67, 98, 100]
