java arraylist to int array code example

Example 1: integer arraylist to int array

//only works in java 8 or later
list.stream().mapToInt(i -> i).toArray();

Example 2: convert array of int to arraylist java

int[] ints = {1, 2, 3};
List<Integer> intList = new ArrayList<Integer>(ints.length);
for (int i : ints)
{
    intList.add(i);
}

Example 3: convert Integer arraylist to array java

Your_ArrayList_Name.stream().mapToInt(k->k).toArray();