C# Example to get SubDomain From URL

C# utility function to find sub domain name from URL. Make Uri object from string url and call below method.


public static string GetSubDomain(Uri url)
    if (url.HostNameType == UriHostNameType.Dns)
        var host = url.Host;
        if (host.Split(\'.\').Length > 2)
            var lastIndex = host.LastIndexOf(".");
            var index = host.LastIndexOf(".", lastIndex - 1);
            return host.Substring(0, index);

    return null;

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