Counting Letters using Arrays

[bgroves85]

If you cast a character as an integer, that character's ascii value will be returned. Uppercase letters have ascii values between 65 and 90 and lowercase letters have ascii values between 97 and 122.

A more complete ascii table can be found here: http://www.asciitable.com/

You may be able to use this in your helper isLetter() method.

Also there are a couple things about the code you posted:

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

   if(isLetter(s.charAt(i))){
      counts[i - 'a']++;  /* the 'i' here refers to an index into the String, not the character itself */
   }
   else{
   } /* your braces seem to mess up starting here */
   counts[26]++;
}
return counts;
}