Question

I have a recursive method that reversed a string (HW assignment, has to be recursive). I did it….but its only returning the value of the string after the first pass. By analyzing the output after each pass i can see it does do its job correctly. heres my code, and the output i get below it:

    String s = "Hello, I love you wont you tell me your name?";
int k=0;
public String reverseThisString(String s) {
    if(k!=s.length()) {
        String first =s.substring(0,k)+s.charAt(s.length()-1);
        String end = ""+s.substring(k, s.length()-1);
        k++;
        s=first+end;
        System.out.println(s);
        this.reverseThisString(s);
    }
    return s;
}

output:

?Hello, I love you wont you tell me your name

Answer 1

I think you need to change this:

this.reverseThisString(s);

to this:

return this.reverseThisString(s);

otherwise the result of the method call is simply discarded.

I would also recommed that you change k to be a parameter to the method rather than a member.