Trying to add a character before each vowel in a String

Question

I want to insert an "ab" before every vowel in a word

Example, if the user enters the word: fire it has to be changed to: fabirabe but my code is only entering the ab before the word like: abfire. How can I fix that?

Here's my code so far:

import java.util.Scanner;
public class Foothill
{ 
   // class variables shared by more than one method
    String prompt;
    static String strUserResponse;

    // main method
    public static void main (String[] args)
    {
        giveInstructions();
        getUserInput();  
        convertToTurkeyIrish();
        vowelCounter();
    }
    public static String convertToTurkeyIrish()
    {

        String turkeyIrish = strUserResponse;
        String turkeyIrish2;
        turkeyIrish2 = "ab" + strUserResponse.replaceAll("(aeiouAEIOU)", "$1ab");
        System.out.println("Word In Turkey Irish: " +  turkeyIrish2);
        return turkeyIrish;
    }

    public static void vowelCounter()
    {
        int vowel = 0;
        strUserResponse.length();
        char vowels;
        vowels = ' ';
        for (int j = 0; j <= strUserResponse.length() - 1 ; j++)
        {
            vowels = strUserResponse.charAt(j);
            if  ((vowels == 'a') || (vowels == 'A') || (vowels == 'e') ||   (vowel == 'E') || (vowel == 'i')|| (vowels == 'I') || (vowels == 'o')  (vowels == 'O') || (vowel == 'u') || (vowels == 'u'))
            {
                System.out.println("Vowels in " + strUserResponse + ": " + vowel++);
            }
        }
    }
}

Answer 1

Your regex is wrong, and so is the replace string. Try this:

strUserResponse.replaceAll("([aeiouAEIOU])", "ab$1");

Answer 2

Change your regex to:

(?i)(a|e|i|o|u)

and the replacement to:

ab$1

Your current regex is aeiouAEIOU which matches a sequence of characters: "aeiouAEIOU".

---

Test it:

System.out.println("fire".replaceAll("(?i)(a|e|i|o|u)", "ab$1"));
// fabirabe

Or as suggested by @amit, you can simply use a character class and write [aeiou]. Note that I used the (?i) to indicate that the regex should be case insensitive.