Replace multiple of the same char in a char array

Question

I am working on a "guess the secret word" game in Java. I have a char array containing _'s relative to the amount of letters in the secret word. I am writing a method that will replace the _'s with the guessed letter. My problem is when I have multiple of the same letters; only the first occurrence is replaced. This is my code:

public void replaceBlank(char letter){
    if(guessLetter(letter)==true){
        int x=getSecretWord().indexOf(letter);
            charArray[x]=letter;
        }
   }

The code inside the if is the piece that deals directly with replacing the _'s. I'm thinking that I need a for loop, but I'm not sure how to implement it.

Answer 1

indexOf returns only the index of the first occurrence of a character. Instead of using it, I'd treat the secret word as an array and just iterate over it:

public void replaceBlank(char letter) {
    char[] secret = getSecretWord().toCharArray();
    for (int i = 0; i < secret.length; ++i) {
        if (secret[i] == letter) {
            charArray[i] = letter;
        }
    }
}

Answer 2

You have to loop through the whole array, for each index check if it's the letter, then replace.