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) {
        if(s == null || s == " ")
            return 0;
        
        char[] arr = s.trim().toLowerCase().toCharArray();
        int count = 0;
        for(int i = 0; i < arr.length; i++){
            char c = arr[i];
            if((c >= 'a' && c <= 'z')){
                count++;
            }else{
                count = 0;
            }
        }
        return count;
    }
}

public class Solution {
    public int lengthOfLastWord(String s) {
        if(s == null || s == " ")
            return 0;
        
        String[] arr = s.split(" ");
        
        if(arr.length != 0)
            return arr[arr.length -1].length();
        else 
            return 0;
    }
}