LengthOfLastWord,字符串最后一个子串的长度

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 LengthOfLastWord 
{
	public int lengthOfLastWord(String s)
	{
		if(s!=null && !s.trim().equals(""))//equals比较的是内容，==比较的是地址
		{
			//去掉开始和结尾的空格
			String[] arr = s.trim().split(" ");
			int len = arr[arr.length - 1].length();
			return len;
		}
		return 0;
	}
}