Length of Last Word

Given a string s consists of upper/lower-case alphabets and empty space characters ' ', return the length of last word in the string.

If the last word does not exist, return 0.

Note: A word is defined as a character sequence consists of non-space characters only.

For example,

Given s = "Hello World",

return 5.

Solution:

  1. public class Solution {
  2.   public int lengthOfLastWord(String s) {
  3.     if (s == null)
  4.       return 0;
  6.     int i = s.length() - 1;
  8.     while (i >= 0 && s.charAt(i) == ' ') { i--; }
  10.     int j = i;
  12.     while (i >= 0 && s.charAt(i) != ' ') { i--; }
  14.     return j - i;
  15.   }
  16. }