Question

private String kNow(String state, String guess) {
        for (int i = 0; i < word.length(); i++) {
            if (guess.equals(word.charAt(i))) {
                state.charAt(i) = word.charAt(i);
            }
        }
        return state;
    }

state.charAt(i) part points the problem in the title.
How can I solve the problem, if my approach is not completely wrong.

Answer 1

The reason this doesn’t work is because charAt(int x) is a method of the String class – namely it is a function, and you can’t assign a function a value in Java.

If you want to loop through a string character by character, I might be tempted to do this:

Char[] GuessAsChar = guess.toCharArray();

Then operate on GuessAsChar instead. There are, depending on your needs, possibly better (as in neater) ways to approach searching for character equivalence in strings.