How do I print a string from a word array, including its duplicates?

Question

I have implemented the following code to try and sort an ArrayList based on the arrangement of my variable, wordToGuess, without using the Comparator class. This works for Strings that have no duplicate letters like "hoarse".

However, the problem arises when I change wordToGuess into "stellar". I do realise that the issue stems from indexOutOfBoundExceptionError but I have thought over a whole day and cant seem to find a probable solution.

My main issue is shifting the whole word "stellar" into my orderedHint ArrayList while keeping both 'l's inside.

Any help is very appreciated!! If you have a better suggestion on how I can sort an ArrayList without using another Comparator class, I will most definitely learn from it! Looking forward to your answers! :D

import java.util.ArrayList;
import java.util.List;

public class ArrayListTest {
    public static List<Character> hints = new ArrayList<Character>();
    public static List<Character>  orderedHint = new ArrayList<Character>();
    public static String wordToGuess = "hoarse";
    public static String word = "";
    public static String fullWord = "";

public static void sortHintsArray() {
    System.out.println("hints: " + hints);
    System.out.println("orderedHint: " + orderedHint);
    for(int i = 0;i<hints.size();i++)
    {

        int index = wordToGuess.indexOf(hints.get(i));
        orderedHint.set(index,hints.get(i));
        System.out.println();
        System.out.printf("%d iteration: \n",i+1);
        System.out.println("hints: " + hints);
        System.out.println("orderedHint: " + orderedHint);
    }
    for(int i =0;i<wordToGuess.length();i++)
    {
        fullWord += orderedHint.get(i);
    }

}

public static boolean checkCorrect() {

    return fullWord == word;
}

public static void main(String[] args) {
    hints.add('e');
    hints.add('r');
    hints.add('s');
    hints.add('a');
    hints.add('h');
    hints.add('o');
    orderedHint.add('e');
    orderedHint.add('r');
    orderedHint.add('s');
    orderedHint.add('a');
    orderedHint.add('h');
    orderedHint.add('o');


    sortHintsArray();
    //System.out.println(hints);
    System.out.println(fullWord);
    }
}

OUTPUT:

hints: [e, r, s, a, h, o]
orderedHint: [e, r, s, a, h, o]

1 iteration: 
hints: [e, r, s, a, h, o]
orderedHint: [e, r, s, a, h, e]

2 iteration: 
hints: [e, r, s, a, h, o]
orderedHint: [e, r, s, r, h, e]

3 iteration: 
hints: [e, r, s, a, h, o]
orderedHint: [e, r, s, r, s, e]

4 iteration: 
hints: [e, r, s, a, h, o]
orderedHint: [e, r, a, r, s, e]

5 iteration: 
hints: [e, r, s, a, h, o]
orderedHint: [h, r, a, r, s, e]

6 iteration: 
hints: [e, r, s, a, h, o]
orderedHint: [h, o, a, r, s, e]
hoarse

Answer 1

The issue is mostly because of the use of String.indexOf which would always return the first occurrence index, hence failure for strings which have duplicate characters .

int index = wordToGuess.indexOf(hints.get(i));

Important : I could confirm this would fail when your hints on the other hand does not have repetitive characters. For example this would fail for

List<Character> hints = List.of('s','t','e','l','a','r');

but not

List<Character> hints = List.of('s','t','e','l', 'l', 'a','r');

Soln : You might either want to keep a track of until what index you've already scanned a letter for and then use indexOf(int ch, int fromIndex) or maybe think of a better design.

Note : Another line of code pinching me is

fullWord += orderedHint.get(i); 

Try avoiding concatenating string within a loop, plan of using StringBuilder .