# When '//' in template literal is used in a HTML file in script editor, it is used as a comment start

Gists

## Overview

When // in template literal is used in a HTML file in script editor, it is used as a comment start.

const sample = //;


For example, when above script is used in a HTML file at the script editor, ;" of const sample =//; is used as the comment.

## Description

### Flow

1. Create new Spreadsheet and open the script editor. In this explanation, please use the container-bound script.

2. Put the following script to Code.gs.

function openDialog() {
const html = HtmlService.createHtmlOutputFromFile("index");
}

1. Create a HTML file as index, and put the following script to the created HTML file.
<script>
const sample = //;
</script>

• At the script editor, please run “openDialog”. And please open the console.
• Please replace // to "//" , "//" , '//', '//' and \/\/. And test them.
1. By this, you can see that the error of Uncaught SyntaxError: Invalid or unexpected token occurs only when const sample = //; is tested. The result is as follows.
• const sample = //; occurs an error like above.
• const sample = "//"; occurs no error.
• const sample = "//"; occurs no error.
• const sample = '//'; occurs no error.
• const sample = '//'; occurs no error.
• const sample = \/\/; occurs no error.

From these results, it is considered that when // is used without enclosed by the double quotes and the single quotes in the template literal, it is used as the comment start. As the current workaround, \/\/ can be used.

By the way, when const sample = //; is used as the Google Apps Script side (Code.gs), no error occurs. So I thought that this might be the current specification or a bug.

This has been mentioned by this thread ( https://stackoverflow.com/q/61692427 ).