Consider using System.IO.Path.Combine() instead of string concatenation

Let's review the following code for creating a file path:

public string GetFullPath(string fileName)
{
      string folder = ConfigurationManager.
              AppSettings["MyFolder"];
      return folder + fileName;
}

This code is prone to error. For example, when you set the folder setting, you have to remember to make sure it ends with a slash. To avoid such problems use Path.Combine() method which will ensure that the folder has ending slash:

public string GetFullPath(string filename)
{
     string folder = ConfigurationManager.
              AppSettings["MyFolder"];
     return Path.Combine(folder, filename);
}

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