Recursive and iterative methods java

package javam;
/**
 * @author Samuel Finocchio
 * Recursive and iterative methods
 */

public class Javam {
    static boolean findLetter(int[] arr, int n, int toFind) {
        // if the whole array does not contain TO_FIND
        if(n == arr.length) return false;

        // if the TO_FIND constant is inside the array
        if(arr[n] == toFind) return true;

        // If the array is not finished yet and nothing was already found
        return findLetter(arr, n + 1, toFind);
    }

    public static int min (int vet[], int min, int position) {
        // If the whole array was parsed
        if(position == vet.length)
            return min;

        // if the current vet value is less then the current min
        if (vet[position] < min)
            min = vet[position];

        // if not the next element is returned with the current position incremented
        return min(vet, min, position + 1);
    }

    public static int max (int vet[], int max, int position) {
        // If the whole array was parsed
        if(position == vet.length)
            return max;

        // if the current vet value is greater then the current min
        if (vet[position] > max)
            max = vet[position];

        // if not the next element is returned with the current position incremented
        return max(vet, max, position + 1);
    }

    public static int sum (int vet[], int position, int sum) {
        // If the whole array was parsed
        if(position == vet.length)
            return sum;

        // Sum gets incremented by the current element of the array
        sum += vet[position];

        // Sum is called with the next position
        return sum(vet, position + 1, sum);
    }

    public static int sum (int vet[][], int firstIndex, int secondIndex, int sum) {
        // vet[firstIndex][secondIndex]

        // If the whole array was parsed
        if(firstIndex == vet.length - 1 && secondIndex == vet[firstIndex].length)
            return sum;

        // If a row in the array is parsed but there is anotherone
        if(secondIndex == vet[firstIndex].length)
            return sum(vet, firstIndex + 1, 0, sum);

        // Sum gets incremented by the current element of the array
        sum += vet[firstIndex][secondIndex];

        // Sum is called with the next position
        return sum(vet, firstIndex, secondIndex + 1, sum);
    }

    public static char[] select(String s, int array[], char selectedArray[], int position) {
        // if the whole array is parsed
        if(position == array.length)
            return selectedArray;

        // assigns the relative position found in array of index specified by position in selected array of index position
        selectedArray[position] = s.charAt(array[position]);

        // returns select with the next position
        return select(s, array, selectedArray, position + 1);
    }

    public static String separate(String s, char separator)
    {
        String newS = "";
        // Foreach character in s
        for(int i = 0; i < s.length() - 1; i++){
            // Attaches the char at position i and the separator
            newS += s.charAt(i);
            newS += separator;
        }
        newS += s.charAt(s.length() - 1);
        return newS;
    }

    public static String separateR (String s, String newS, char separator, int position)
    {
        if(position == s.length() - 1)
            return newS + s.charAt(s.length() - 1);

        newS += s.charAt(position) + Character.toString(separator);
        // newS += separator;

        return separateR(s, newS, separator, position + 1);
    }

    public static void main(String[] args) {
        int vet[] = {3, 1, 2, 3, 1};
        int vetBi[][] = {
            {0,3, 1},
            {-1, 3, 2},
            {0, 1, 1},
            {1, 2 ,2},
            {0, 1, 1}
        };

        // findLetter(array, counter to 0, number to find)
        System.out.println("Find letter: " + findLetter(vet, 0, 5));

        // min (array, first element used to compare, counter to 0)
        System.out.println("Min: " + min (vet, vet[0], 0));

        // max (array, first element used to compare, counter to 0)
        System.out.println("Max: " + max (vet, vet[0], 0));

        // sum (array, position, starting sum from 0)
        System.out.println("Sum: " + sum (vet, 0, 0));

        // sum overloaded (array, position1, position2, starting sum)
        System.out.println("Sum 2: " + sum(vetBi, 0, 0, 0));

        // For each char generated by the method select
        for (char
                // select ("string in witch characters are picked", vector of positions, array to create )
                c:select("wkci2", vet, new char["wkci2".length()], 0))
            System.out.print(c);

        System.out.println();

        // separateR(initial string, empty starting, separator, starting from 0)
        System.out.println(separateR("FreeSoftware", "", '_', 0));
    }
}