How to use js to know if a page is open in a new tab?

Question

JavaScript

How to use js to know if a page is open in a new tab?
And, if it's not difficult for you to write a script, then how to assign the value style="display: none" to a block with id="back" if the page on which this block is opened in a new tab?

Answer 1

document.getElementById('back').style.display = (window.history.length == 1) ? "none" : "";

Answer 2

javascript.ru/tutorial/dom/intro#style
To recognize "open in a new tab", the sessionStorage object is used .