Convert ArrayList<Integer> to a primitive int[] array

ArrayListIntegerToIntArray.kt

import java.util.ArrayList;
import java.util.Arrays;

// Your ArrayList of Integers
ArrayList<Integer> arrayList = new ArrayList<>(Arrays.asList(1, 2, 3, 4, 5));

// Convert it to a primitive int[] array
int[] primitiveArray = arrayList.stream()
                                .mapToInt(Integer::intValue)
                                .toArray();

// The result
System.out.println(Arrays.toString(primitiveArray)); // Output: [1, 2, 3, 4, 5]