Question

I have the following code:

    int t = s.length()-1;
    int g = 0;

    for (int i=0; i < s.length(); i++){

        if (s.charAt(i) != h.charAt(t--));
            g++;

    }

    if (g==0)
        return true;

    else 
        return false;

Basically what this code is suppose to do is to test if string h’s inverse is equal to string s, or vice versa. For some reason a “false” is always returned – although the obvious answer is true.

Can anyone please tell me what’s wrong with my code?

Thanks!

Answer 1

I’d say an extra ; is the culprit.

Instead of

if (s.charAt(i) != h.charAt(t--));

use

if (s.charAt(i) != h.charAt(t--))

You should always go the “safe” route. That is, use braces after if-else statements (and pretty much everywhere you can use them), so bugs like this won’t happen in the first place. The correct way to write it is:

if (s.charAt(i) != h.charAt(t--)) {
   g++;
}

And by the way, your code will blow up if you don’t check first that s and h have the same length.