Set toArray() method in Java with Example

The toArray() method of Java Set is used to form an array of the same elements as that of the Set. Basically, it copies all the element from a Set to a new array.
Syntax:

Object[] toArray()

Parameters: The method takes optional parameter. If we provide the type of Object array we want we can pass it as an argument. for ex: set.toArray(new Integer[0]) returns an array of type Integer, we can also do it as set.toArray(new Integer[size]) where size is the size of the resultant array. Doing it in the former way works as the required size is allocated internally. 
Return Value: The method returns an array containing the elements similar to the Set.
Below programs illustrate the Set.toArray() method:
Program 1:

Java

// Java code to illustrate toArray()

import java.util.*;

public class SetDemo {
    public static void main(String args[])
    {
        // Creating an empty Set
        Set<String> abs_col = new HashSet<String>();

        // Use add() method to add
        // elements into the Set
        abs_col.add("Welcome");
        abs_col.add("To");
        abs_col.add("Geeks");
        abs_col.add("For");
        abs_col.add("Geeks");

        // Displaying the Set
        System.out.println("The Set: "
                           + abs_col);

        // Creating the array and using toArray()
        Object[] arr = abs_col.toArray();

        System.out.println("The array is:");
        for (int j = 0; j < arr.length; j++)
            System.out.println(arr[j]);
    }
}

Output:

The Set: [Geeks, For, Welcome, To]
The array is:
Geeks
For
Welcome
To

Program 2:

Java

// Java code to illustrate toArray()

import java.util.*;

public class SetDemo {
    public static void main(String args[])
    {
        // Creating an empty Set
        Set<Integer> abs_col = new HashSet<Integer>();

        // Use add() method to add
        // elements into the Set
        abs_col.add(10);
        abs_col.add(15);
        abs_col.add(30);
        abs_col.add(20);
        abs_col.add(5);
        abs_col.add(25);

        // Displaying the Set
        System.out.println("The Set: " + abs_col);

        // Creating the array and using toArray()
        Integer[] arr = abs_col.toArray(new Integer[0]);

        System.out.println("The array is:");
        for (int j = 0; j < arr.length; j++)
            System.out.println(arr[j]);
    }
}

Output:

The Set: [20, 5, 25, 10, 30, 15]
The array is:
20
5
25
10
30
15

Reference: https://docs.oracle.com/javase/7/docs/api/java/util/Set.html#toArray()