Why am i getting IndexOutOfBoundsException here?

Question

import java.util.*;

class two_strings_annagrams1 {
    public static boolean compute(String inp1, String inp2) {
        ArrayList<Character> hs = new ArrayList<Character>();
        for (int i = 0; i < inp1.length(); i++) {
            hs.add(inp1.charAt(i));
        }
        System.out.println(hs);
        for (int j = 0; j < inp2.length(); j++) {
            hs.remove(inp2.charAt(j));
        }
        System.out.println(hs);
        if (hs.size() == 0) {
            return true;
        }
        return false;
    }

    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        String inp = s.nextLine();
        String inp2 = s.nextLine();
        System.out.println(compute(inp, inp2));
    }
}

When I use ArrayList or LinkedList I'm getting an IndexOutOfBounds Exception but when I use HashSet the code is working fine. What's the reason of exception and how the exception can be resolved?

Answer 1

I think hs.remove(inp2.charAt(j)) resolves to remove(int), not remove(Character), because the compiler prefers expanding a char to an int over boxing it to a Character.

If you use

hs.remove((Character) inp2.charAt(j))

it will eliminate the ambiguity.