Validate a barcode UPC-E, UPC-A, EAN, EAN-14, SSCC

validate_barcode.js

// checksum calculation for GTIN-8, GTIN-12, GTIN-13, GTIN-14, and SSCC
// based on http://www.gs1.org/barcodes/support/check_digit_calculator
function isValidBarcode(barcode) {
  // check length
  if (barcode.length < 8 || barcode.length > 18 ||
      (barcode.length != 8 && barcode.length != 12 &&
      barcode.length != 13 && barcode.length != 14 &&
      barcode.length != 18)) {
    return false;
  }

  var lastDigit = Number(barcode.substring(barcode.length - 1));
  var checkSum = 0;
  if (isNaN(lastDigit)) { return false; } // not a valid upc/ean

  var arr = barcode.substring(0,barcode.length - 1).split("").reverse();
  var oddTotal = 0, evenTotal = 0;

  for (var i=0; i<arr.length; i++) {
    if (isNaN(arr[i])) { return false; } // can't be a valid upc/ean we're checking for

    if (i % 2 == 0) { oddTotal += Number(arr[i]) * 3; }
    else { evenTotal += Number(arr[i]); }
  }
  checkSum = (10 - ((evenTotal + oddTotal) % 10)) % 10;

  // true if they are equal
  return checkSum == lastDigit;
}

validate_barcode_function.rb

def valid_upc(upc)
  # check length
  if (upc.length < 8 or upc.length > 18 or
       (upc.length != 8 && upc.length != 12 &&
        upc.length != 13 && upc.length != 14 &&
        upc.length != 18)
     )
    return false
  end

  last_digit = upc.slice!(-1).to_i
  check_sum = 0

  arr = upc.split(//).reverse
  odd_total = even_total = 0

  arr.each_index do |i|
    if (i % 2 == 0)
      odd_total = odd_total + (arr[i].to_i * 3)
    else
      even_total = even_total + arr[i].to_i
    end
  end
  check_sum = (10 - ((even_total + odd_total) % 10)) % 10

  # true if they are equal
  return check_sum == last_digit
end

Also I contribute a (very) condensed python chunk to add to your gist:

def validate_length(barcode: str) -> bool:
    return len(barcode) in (8, 12, 13, 14, 18)


def validate_check_digit(barcode: str) -> bool:
    result = sum(
        i * 3 if idx % 2 == 0 else i
        for idx, i in enumerate(
            (int(i) for i in barcode),
        )
    )

    return result % 10 == 0


def validate_barcode(barcode: str) -> bool:
    return validate_length(barcode) and validate_check_digit(barcode)

Bye.

Hi, I am trying to use this code in a Google Sheet as a custom function and I admit that I'm a bit out of my depth. I have written Bash scripts, but js is outside my wheelhouse. All my efforts so far just lead to more execution errors.

Is there any chance someone could help convert this to be used as a function in Google Sheets?
Thanks either way!

The JS version does not have barcode.length != 12 at the beginning.

that only applies for a generic UPC an EAN is 13, so no the suggestion is not valid