Casting ArrayList<String> to String[]

Question

1) I am wondering why I can't do this:

ArrayList<String> entries = new ArrayList<String>();
entries.add("entry");
String[] myentries = (String[])entries.toArray();

What's wrong with that? (You might ignore the second code line, it's not relevant for the question)

2) I know my goal can be reached using this code:

ArrayList<String> entries = new ArrayList<String>();
entries.add("entry");
String[] myentries = new String[entries.size()];
myentries = entries.toArray(myentries)

Is this the prefered way of converting the ArrayList to a String Array? Is there a better / shorter way?

Thank you very much :-)

Answer 1

The first example returns an Object[] as the list doesn't know what type of array you want and this cannot be cast to a String[]

You can make the second one slightly shorter with

String[] myentries = entries.toArray(new String[entries.size()]);

Answer 2

The backing array created by the ArrayList isn't a String array, it's an Object array, and that's why you can't cast it.

Regarding case 2. That's the common way to convert it to an array, but you can make it a bit less verbose by writing:

String[] myentries = entries.toArray(new String[entries.size()]);