I love JavaScript. I don't know why but I do.

However if you want to loop over an indeterminate-size list of URLs to find out when each page last changed, it seemed hard -- until I remembered tail recursion, which is pretty simple -- but I don't see many people talking about it. So I thought I'd write it up.

Here's how it works

1. Arrange all the URLs in an array.

2. Write a routine that reads one URL.

3. When it completes, it recursively calls itself for the next item in the array.

4. When you fall off the array, return.