How to replace first letter and last letter in array of strings

I am trying to replace in the array of strings in EVERY word, the first letter with A and the last letter with Z

My Array :

String[] replaceFirstLetter1 = new String[]{"Java Bople Orange New Dog Cat"};

This is what I am trying:

  public static String[] replaceFirstLetterWithZ(String[] replaceFirstLetter) {
        String[] tempTable = new String[replaceFirstLetter.length];
        StringBuilder stringBuilder = new StringBuilder();
        for (int i = 0; i < replaceFirstLetter.length; i++) {
            stringBuilder.append(replaceFirstLetter[i]);
            stringBuilder.replace(0, replaceFirstLetter.length, "A");
            stringBuilder.replace(replaceFirstLetter.length-1, replaceFirstLetter.length, "Z");
            tempTable[i] = stringBuilder.toString();
        }
        return tempTable;
    }

Anyhow my output is not what I am expecting
Output:

[Zava Bople Orange New Dog Cat]

Can any of you give a hand on what and where I should look for my mistake ?
Thanks

>Solution :

Regex is the goto tool here.

To replace the first and last words of every word in a string with A and Z:

str = str.replaceAll("\\w(\\w*)\\w", "A$1Z");

This works by matching words but capturing all characters of the word except the first and last characters, and replacing the match with A-group1-Z.

FYI words of only 1 letter are not matched.

To apply this to an array of String:

for (int i = 0; i < array.length; i++) {
    array[i] = array[i].replaceAll("\\w(\\w*)\\w", "A$1Z");
}