It's not the best decision, but I was afraid of different type of spaces like wide space or thin space etc.

so I used Character.isWhitespace(char ch);

```
class Solution {
public int lengthOfLastWord(String s) {
if(s == null || s.length() == 0) return 0;
int result = 0;
int space = 0;
while(Character.isWhitespace(s.charAt(s.length()-1))
&& s.length() > 0) {
s = s.substring(0, s.length()-1);
if(s.length() < 2) break;
}
for(int i = s.length()-1; i >= 0; i--) {
if(Character.isWhitespace(s.charAt(i))) {
space = i+1;
break;
}
}
result = s.length() - space;
if(result < 1) return 0;
return result;
}
}
```