using System;
using System.Collections.Generic;
using System.IO;
using System.Text;

namespace CSVDemo
{
  /// <summary>
  /// CSVUtil is a helper class handling csv files.
  /// </summary>
  public class CSVUtil
  {
    private CSVUtil()
    {
    }
    //write a new file, existed file will be overwritten
    public static void WriteCSV(string filePathName,List<String[]>ls)
    {
      WriteCSV(filePathName,false,ls);
    }
    //write a file, existed file will be overwritten if append = false
    public static void WriteCSV(string filePathName,bool append, List<String[]> ls)
    {
      StreamWriter fileWriter=new StreamWriter(filePathName,append,Encoding.Default);
      foreach(String[] strArr in ls)
      {
        fileWriter.WriteLine(String.Join (“,",strArr) );
      }
      fileWriter.Flush();
      fileWriter.Close();
      
    }
    public static List<String[]> ReadCSV(string filePathName)
    {
      List<String[]> ls = new List<String[]>();
      StreamReader fileReader=new  StreamReader(filePathName); 
      string strLine="";
      while (strLine != null)
      {
        strLine = fileReader.ReadLine();
        if (strLine != null && strLine.Length>0)
        {
          ls.Add(strLine.Split(','));
          //Debug.WriteLine(strLine);
        }
      } 
      fileReader.Close();
      return ls;
    }
    
  }
}