In this article we will discuss how to convert a HashSet in to an array.

Each collection that provides a member function toArray() i.e.

It iterates through all the elements of Collection (HashSet in our case) and set the each elements in the passed argument array []a. But if array [] a ‘s length is less than the Collection’s size then it will create a new array of required size and initialize elements in it.

Checkout the following example to convert HashSet into an array.

Output:

As you can see the last element is null. It is because we created the array of size 5 but in HashSet there were only 4 elements. Remaining elements in array will be set to null.

 

Remember if passed array’s length is less than the Collection’s size then it will internally create a new array of required size, then set elements in it and then returns it. Therefore, always use the array returned by toArray() not the array passed.