make arrayList.toArray() return more specific types

The Solution to make arrayList.toArray() return more specific types is


Like this:

List<String> list = new ArrayList<String>();

String[] a = list.toArray(new String[0]);

Before Java6 it was recommended to write:

String[] a = list.toArray(new String[list.size()]);

because the internal implementation would realloc a properly sized array anyway so you were better doing it upfront. Since Java6 the empty array is preferred, see .toArray(new MyClass[0]) or .toArray(new MyClass[myList.size()])?

If your list is not properly typed you need to do a cast before calling toArray. Like this:

    List l = new ArrayList<String>();

    String[] a = ((List<String>)l).toArray(new String[l.size()]);

~ Answered on 2011-02-21 02:19:32


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