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;
    }
};