I'm trying to write JavaScript code that acts like Excel custom formatting: taking a format and applying it to a string/number/etc in a HTML table.
Is there some code or library that'll let me do that? I'm not trying to access Excel files, just copy the custom format functionality.
If you are using nodejs then please use a framwork that can handle the excel operations. With that you can easily manipulate Excel files. There is one here try it: https://www.npmjs.com/package/exceljs