Without using trim/indexOf functions

[era.ch]

    public int lengthOfLastWord(String s) {
        int length = 0;
        int i = s.length()-1 ;
        while(i>=0){
            if(s.charAt(i) == ' ' && i == s.length()-1){
               while( i >= 0 && s.charAt(i) == ' ') i--;
            }
            while(i >= 0 && s.charAt(i) != ' '){
                length++;
                i--;
            }
            break;
        }
        return length;
    }
}