title: How Do I add data in the notepad .txt file in C#?
body: <p>I am able to write new data into the .txt file. But, it comes as the replacement of the existing data.
  So, how can I add new data to the file by keeping the existing data already present in the .txt file.
  I have been using <code>System.IO</code> namespace and <code>StreamWriter</code> to edit data.</p>
  
  <pre><code>StreamWriter EditEmployeeDetail =
      new StreamWriter(@"C:\Users\user\Desktop\FoodDeliverySystem\Employee_details.txt");
  EditEmployeeDetail.Write(temp_Emp_Det);
  EditEmployeeDetail.Close();
  </code></pre>