package uebung33;

public class ReplaceVowels extends Object {

	// Rekursiv:
	public static String replaceVowels(String s) {
		String result = replaceVowels(s, 0);
		return result;
	}

	// Rekursive Hilfsmethode:
	private static String replaceVowels2(final String s, int i) {
		if (i >= s.length())
			return "";

		char c = s.charAt(i);
		if (c == 'a' || c == 'e' || c == 'i' || c == 'o' || c == 'u')
			c = 'x';
		else if ("AEIOU".indexOf(c) != -1) // geht alternativ wie im if
			c = 'X';

		return c + replaceVowels(s, i + 1);
	}
	
	private static String replaceVowels(String s, int i) {
		if (i < s.length()) {		
			char c = s.charAt(i);
		
			if (c == 'a' || c == 'e' || c == 'i' || c == 'o' || c == 'u')
				c = 'x';
			else if (c == 'A' || c == 'O')
				c = 'X';
		
			i++;
			String ergebnis = c + replaceVowels(s, i);
			return ergebnis;
		} else {
			return "";
		}
	}
	
	// Iterativ:
	static String replaceVowelsIter(String s) {
		String result = "";
		
		for (int i = 0; i < s.length(); i++) {
			char c = s.charAt(i);

			if (c == 'a' || c == 'e' || c == 'i' || c == 'o' || c == 'u')
				result = result + 'x';
			else if (c == 'A' || c == 'O' || c == 'U' || c == 'I' || c == 'E')
				result = result + 'X';
			else
				result = result + c;
		}
		
		return result;
	}

	public static void main(String[] args) {
		System.out.println(replaceVowels("Beispiel Anfang Und"));
	}
}