Replace text stored in string

Question

Using iText 5.5, I am trying to assign value from list to variable. Any professional eager to help amateur?

File I am parsing: https://slicedinvoices.com/pdf/wordpress-pdf-invoice-plugin-sample.pdf

Here is my code:

using iTextSharp.text.pdf;
using iTextSharp.text.pdf.parser;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace PDF_file_reader
{
    class Program
    {
        static void Main(string[] args)
        {

            List<string> InvoiceNumbers = new List<string>();

            string filePath = @"C:\temp\parser\Invoice_Template.pdf";
            int pagesToScan = 2;

            string strText = string.Empty;
            try
            {
                PdfReader reader = new PdfReader(filePath);

                for (int page = 1; page <= pagesToScan; page++) //(int page = 1; page <= reader.NumberOfPages; page++) <- for scanning all the pages in A PDF
                {
                    ITextExtractionStrategy its = new LocationTextExtractionStrategy();
                    strText = PdfTextExtractor.GetTextFromPage(reader, page, its);

                    strText = Encoding.UTF8.GetString(ASCIIEncoding.Convert(Encoding.Default, Encoding.UTF8, Encoding.Default.GetBytes(strText)));
                    //creating the string array and storing the PDF line by line
                    string[] lines = strText.Split('\n');
                    foreach (string line in lines)
                    {
                        if (line.Contains("Invoice Number"))
                        {
                            InvoiceNumbers.Add(line.Trim());
                            break;
                        }
                    }

                    var match = InvoiceNumbers.FirstOrDefault(stringToCheck => stringToCheck.Contains("Invoice Number"));

                    match.Replace("Invoice number", "").Trim();

                    Console.Write(match);

                    Console.Read();
                }

            }
            catch (Exception ex)
            {
                Console.Write(ex);
            }
        }
    }
}

I need match to be INV-3337 currently it seems to be Invoice Number INV-3337. Why this command:

match.Replace("Invoice number", "").Trim();?

does not perform Replace.

My output:

Answer 1

It doesn't work because the match is case sensitive (capital N vs lower case n).

match = match.Replace("Invoice Number", "").Trim();

Answer 2

Instead of writing:

match.Replace("Invoice number", "").Trim();

use:

match = match.Replace("Invoice Number", "").Trim();