Length of Last Word Js

Problem Statement:

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.

Solution:

var lengthOfLastWord = function(s) {
    string=s.trim().split(" ")
    arr=string[string.length-1]
    return(arr.length)
};