Question: I need to print a String letter by letter with a \* between each letter.
I want to find a recursive solution and not an iterative one. The signature must be :

```java
public static String allStar(String a);

```

Answer: 
Beshambher's answer is a neat and easy way to do it. But if you want to do it recursively then :

```java
public static String allStar(String a) {
    if(a == null || a.isEmpty()) {        
        return "";
    }

    if(a.length() == 1) {
        return a;
    }        
    return  a.charAt(0) + "*" + allStar(a.substring(1));
}

```
try this code :

```
public class Main {

static String Answer = "" ;

    public static void main(String[] args) {

        Main.SetStarAfterEachLetter("hello!");

        System.out.println(Answer);

    }

public static void SetStarAfterEachLetter(String letter){

    Answer = Answer + letter.charAt(0);
    Answer = Answer + " * ";
    letter = letter.substring(1);

    if(!letter.isEmpty()) {
        SetStarAfterEachLetter(letter);
    }
}

```

}