Question

If you have an instance of a Collection, say something like:

Collection<String> addresses = new ArrayList<String>(); 

Which were to then be populated with a bunch of values, which is the ‘best’ way, if any, to make use of the toArray() method without requiring a type cast?

String[] addressesArray = addresses.toArray(new String[] {}); String[] addressesArray = addresses.toArray(new String[0]); String[] addressesArray = addresses.toArray(new String[addresses.size()]); String[] addressesArray = addresses.toArray(new String[addresses.size() + 5]); 

Is there any semantic difference between the first two? Is the third most efficient? Is the fourth less efficient than the third?

Answer 1

According to a findbugs report, this is the most efficient:

String[] addressesArray = addresses.toArray(new String[addresses.size()]); 

I believe them 😉