validate barcodes so that only valid 13-digit numeric barcodes

Uncategories validate barcodes so that only valid 13-digit numeric barcodes

string barcodes = string.Join(",",

result.data

.Where(a => !string.IsNullOrEmpty(a.BarcodeValue)) // ignore null/empty

.Select(a =>

{

// Try to parse only numeric barcodes

if (long.TryParse(a.BarcodeValue, out long num))

{

// Return exactly 13 digits

return num.ToString().PadLeft(13, '0');

}

return null; // reject invalid ones

})

.Where(b => b != null && b.Length == 13) // keep only 13-digit results

);

Ex:

[

{ "BarcodeValue": "0507510108257" },

{ "BarcodeValue": "0001234" },

{ "BarcodeValue": "7890" },

{ "BarcodeValue": "ABC123" } // invalid

]

Op:

0507510108257,000000001234,000000007890