endsWith in JavaScript

How can I check if a string ends with a particular character in JavaScript?

Example: I have a string

var str = "mystring#";

I want to know if that string is ending with #. How can I check it?

1. Is there a endsWith() method in JavaScript?

2. One solution I have is take the length of the string and get the last character and check it.

Is this the best way or there is any other way?