How can I convert a Java HashSet to a primitive int array?

Question

I\'ve got a HashSet with a bunch of Integers in it. I want to turn it into an array, but calling

hashset.toArray();
         


        

Answer 1

You could also use the toArray(T[] contents) variant of the toArray() method. Create an empty array of ints of the same size as the HashSet, and then pass it to the toArray() method:

Integer[] myarray = new Integer[hashset.size()];
doSomething(hashset.toArray(myarray));

You'd have to change the doSomething() function to accept an Integer[] array instead of int[]. If that is not feasible, you'd have convert the array of values returned by toArray to int[].