"return" problem

Question

Hi, I've a problem with the return statement inside a recursive method, this is the code:
public int indexOf( String s)
smallstring = s;
int counter = 0;
if (text.length() < smallstring.length())
counter = -1;
return counter;
else
if (text.length() == smallstring.length() && text.equals(s))
counter = 1;
return counter;
else
if (text.length() > smallstring.length())
if (text.substring(0,smallstring.length()).equals(smallstring))
counter++;
return counter;
else
String t_one = (text.substring(1));
Index one = new Index (t_one);
one.indexOf(smallstring);
return counter;
I know that I have to give the return statement, but, if I put a return (return counter;) at the end of the method, the method will give me the value "0" forever at the runtime, whatever the case.
How can I solve this problem?
I'll wait for HELP!!!
Thank you

Answer 1

you should think about how recursion wrks. The idea is to solve some simple case, and then somehow revert all cases to the simple case. You're not doing that.
String t_one = (text.substring(1));
Index one = new Index (t_one);int index = one.indexOf(smallstring);
now "index" is the index of the small string in the substring, or -1 if the small string is not found. Knowing this, can you somehow calculate the index of the small string in the longer text?
about the return statements, if you've really considered all the cases, the control won't ever get past the if statement, so it doesn't matter what you write there. You could just aswell put "return -341;", doesn't matter the least bit. But if the control does go there, you should print an error message or raise an exception or something, because it tells you not all cases were considered and the recursion is broken.