It looks like the script is trying to extract email addresses and then remove duplicates using a JavaScript Set. However, if your goal is to remove duplicate records from an entire CSV file, this approach may not work as expected because csvReadArray returns an array structure and not necessarily a simple string that can be processed directly with the regular expression shown.
If the CSV contains only email addresses, you could convert the array to a string first and then apply duplicate filtering. However, for larger CSV files or files containing multiple columns, the process can become complicated and difficult to maintain.
In similar situations, I have found it much easier to use a dedicated CSV duplicate removal tool. For example, I recently worked with a CSV containing thousands of records where duplicate entries were spread across multiple columns. Using a specialized SysTools CSV Duplicate Remover, I was able to identify and remove duplicate rows in just a few minutes without writing or debugging scripts.
If you need to preserve specific records, compare rows based on selected columns, or process large CSV datasets, a dedicated solution is often more reliable than handling everything through custom scripting.
Could you share a sample of your CSV structure? Knowing whether you’re removing duplicate email addresses, duplicate rows, or duplicates based on specific columns would help determine the best approach.