How to store arrayList into an array in java?

Question

How to store arrayList into an array in java?

Answer 1

That depends on what you want:

List<String> list = new ArrayList<String>();
// add items to the list

Now if you want to store the list in an array, you can do one of these:

Object[] arrOfObjects = new Object[]{list};
List<?>[] arrOfLists = new List<?>[]{list};

But if you want the list items in an array, do one of these:

Object[] arrayOfObjects = list.toArray();
String[] arrayOfStrings = list.toArray(new String[list.size()]);

Reference:

• Collection.toArray()
• Collection.toArray(T[])

Answer 2

If Type is known (aka not a generics parameter) and you want an Array of Type:

ArrayList<Type> list = ...;
Type[] arr = list.toArray(new Type[list.size()]);

Otherwise

Object[] arr = list.toArray();