【leetcode】58. 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

.

public class Solution {
public int lengthOfLastWord(String s) {
// //方法1
// int lenIndex = s.length() - 1;//lenIndex ： locate the last non-space character 定位最后一个非空字符的位置。
// int len = 0;//计数
// for (int i = lenIndex; i >= 0 && s.charAt(i) == ' '; i--){
//      lenIndex--;
// }
// for (int j = lenIndex; j >= 0 && s.charAt(j) != ' '; j--){
//     len++;
// }
// return len;

// //方法2 use split;
// String[] words= s.split(" ");
// if (words.length == 0){
//     return 0;
// } else {
//     return words[words.length-1].length();
// }

//方法3 use trim  去除首尾空格
return s.trim().length() - s.trim().lastIndexOf(' ') - 1;
}
}