Table of Contents

Local variables

Local variables must have a meaningful name and camelCasing must be applied.

Hungarian notation

Names of local variables may start with a prefix denoting their type (so-called Hungarian notation), but this is not required.

Hungarian notation allows related variables to have the same name, except for the type prefix. For example, suppose there is a string variable "sStartTime", representing a time. The corresponding variable of type DateTime can then be named "dtStartTime" or "startTime". Without the prefix, it is more difficult to have a unique name for both variables.

In general, using Hungarian notation for all variable names is not encouraged. However, when you do use Hungarian notation, you must use the following prefixes:

  • Built-in Types

    C# type .NET Framework Type Prefix Example
    bool System.Boolean b bIsBusy
    byte System.Byte by byCommand
    sbyte System.SByte sby sbyCommand
    char System.Char c cProtocolType
    decimal System.Decimal dec decSignalStrength
    double System.Double d dSignalStrength
    float System.Single f fSignalStrength
    int System.Int32 i iRowCount
    uint System.UInt32 ui uiRowCount
    long System.Int64 l lErrorCount
    ulong System.UInt64 ul ulErrorCount
    object System.Object o oResponse
    short System.Int16 sh shStatusCode
    ushort System.UInt16 ush ushStatusCode
    string System.String s sResponse

  • Other

    Class Prefix Example
    System.DateTime dt dtNow
    System.TimeSpan ts tsHour
    System.Text.StringBuilder sb sbResponse
    System.Xml.Linq.XDocument
    System.Xml.Linq.XElement
    System.Xml.Linq.XAttribute    		 x xDocument

  • Arrays

    For array variables, the type prefix must be preceded by an additional "a" to indicate an array (e.g. string[] asServiceNames).

  • Strongly Typed Collections (System.Collections.Generic)

    The following table gives an overview of the different prefixes that should be used for collections. In case a collection has only one type (e.g. HashSet<T>), the identifier should include the type prefix (e.g. HashSet<string> hssDevices).

    Plural nouns should be used for lists and sets.

    Class Prefix Example
    Dictionary<TKey, TValue> dict Dictionary<string,string> dictMappings
    HashSet<T> hs HashSet<string> hssDeviceTypes
    LinkedList<T> ll LinkedList<string> llsNames
    List<T> l List<string> lsNames
    Stack<T> s Stack<string> ssCalls
    Queue<T> q Queue<string> qsMessages

  • Private fields

    Private fields may start with an underscore ("_"), followed by the prefix defined above if applicable. However, the use of "this." is favored over the use of underscores to denote a local class field.

  • Booleans

    The name of a local variable of type Boolean should start with a verb (e.g. foundCarrier, isPresent).

  • Enumerations

    For enum variables, the prefix "e" may be used.

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