Length of last word

class Solution {
public:
int lengthOfLastWord(const char *s) {
// Start typing your C/C++ solution below
// DO NOT write int main() function
if (*s == NULL) return 0;

int length = 0;
int result = 0;

while (*s){

if (*s == ' ') {
length = 0;
s++;
}

else {
length++;
result = length;
s++;
}
}

return result;
}
};