The problem is that you didn't include any checks for case or punctuation and white space.
One way you could do it is something like this. The specifics depend on what you're allowed to use for the assignment, but you're probably intended to do something along these lines.
Also, note that toLowerCase
is problematic if you have the default locale set to something unusual like Turkey. For proper robustness, you need to specify a locale, but this isn't something you'll have to worry about in a homework assignment.
public static boolean isSymmetrical(String inputText)
{
inputText = inputText.toLowerCase();
if(inputText.length() == 0 || inputText.length() ==1)
return true;
if(!Character.isLetter(inputText.charAt(0)))
return isSymmetrical(inputText.substring(1,inputText.length()));
if(!Character.isLetter(inputText.charAt(inputText.length()-1)))
return isSymmetrical(inputText.substring(0,inputText.length()-1));
if(inputText.charAt(0) == inputText.charAt(inputText.length()-1))
return isSymmetrical(inputText.substring(1,inputText.length()-1));
return false;
}