Anyone know how to add an int[] array into a 2d ArrayList<ArrayList<Integer>>?
The code...
import java.util.ArrayList;
import java.util.Arrays;
public class Test2 {
public static void main(String[] args) {
int[] intArray = {1,1,1,1};
ArrayList<ArrayList<Integer>> list = new ArrayList<>();
list.add(new ArrayList<Integer>(Arrays.asList(intArray))); // <- compile error
}
}
change your int array to an Integer array.
Integer [] intArray = {1,1,1,1};
int for mutable changes and acquiring results. I was hoping to convert it just before it gets added to the 2d ArrayList. Is it possible to convert while adding it?
int to Integer but no autoboxing from int[] to Integer[]
int and try this list.add(Arrays.stream(intArray).boxed().collect(Collectors.toCollection(ArrayList::new)));String[] array = {"one","one","one","one"}; and ArrayList<ArrayList<String>> list = ArrayList<>(); and then list.add(new ArrayList<String>(Arrays.asList(tempResult)))... it only worked with this because String was the same type, and int and Integer are different and "can't be autoboxed from int[] to Integer[]"?Make your ArrayList an ArrayList of int[]:
ArrayList<int[]> list = new ArrayList<>();
list.add(intArray); // should work now
