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

It fails when the check digit equals 10.
Line #24 should say:

checkSum = (10 - ((evenTotal + oddTotal) % 10)) % 10;

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

@cebence @tompazourek - thank you for your fixes.

Assuming I want to use this code (seems to work fine for me): What is the license type then? Would be nice if you could clarify this.

Just used this gist code in my opensource project that allows you to create & download barcode images for absolutely free. this tool will always be free. Thanks for your contribution making it possible in small time.

https://tools.fromdev.com/bar-code-generator.html

Hello,

What about UPC-E barcodes?

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!