c# zip file and folder programmatically

private static string CompressFile(string sourceFileName)
{
using (ZipArchive archive = ZipFile.Open(Path.ChangeExtension(sourceFileName, ".zip"), ZipArchiveMode.Create))
{
archive.CreateEntryFromFile(sourceFileName, Path.GetFileName(sourceFileName));
}
return Path.ChangeExtension(sourceFileName, ".zip");
}

private static void CompressFloder(string startPath, string zipPath)
{
ZipFile.CreateFromDirectory(startPath, zipPath);
}

private static void UncompressToDirectory(string zipPath, string extractPath)
{
ZipFile.ExtractToDirectory(zipPath, extractPath);
}