In SpreadJS you can add notes to a sheet using comments. Using comments can help you make a sheet easier to understand by providing additional context for the data it contains.
To add a comment to a sheet, first create a comment and set some settings for it. Then you can use the add method to set a comment for the specified cell. For example:
sheet.comments.add(5, 5, 'new comment!');
Sometimes you want to remove the comment you added, as shown in the following example:
After you add a comment to a cell, you can use the get method to get the comment, or use the all method to get all the comments in the sheet.
var comment = sheet.comments.get(5, 5);
var comments = sheet.comments.all();