The tutor talks about ==$zer0 in Chrome’s Developer tools.
Looking at a page source in Google Chrome, I saw the entry ==$0. It wasn’t manifesting on the page itself; I wondered if it was a type of HTML comment.
Apparently, ==$0 shows the element you’ve selected to inspect. Chrome itself prints it in the page source to help you find the line that produces the element you’ve chosen. It’s not content.
Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.