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Syntax of Properties in Class Definitions

Describes the structure of a property definition. Note that a relationship is a property. See Property Definitions for links to general information on defining properties.


A property contains information relevant to an instance of a class. You can add property definitions to object classes. They are not meaningful in other kinds of classes.


A property definition has the following structure:

/// description 
Property name As classname (parameter_list) [ keyword_list ] ;

Or (for a list property):

/// description 
Property name As List Of classname (parameter_list) [ keyword_list ] ;

Or (for an array property):

/// description 
Property name As Array Of classname (parameter_list) [ keyword_list ] ;

Or (for a relationship property):

/// description 
Relationship name As classname [ keyword_list ] ;


  • description (optional) is intended for display in the Class Reference. The description is blank by default. See Creating Class Documentation.

  • name (required) is the name of the property. This must be a valid class member name, and must not conflict with any other class member names.

  • classname (optional) is the name of the class on which this property is based.

  • parameter_list (optional) is a comma-separated list of parameters and their values. If specified, these should be either parameters used by classname or parameters that are available to all properties.

    If this list is omitted, also omit the parentheses.

  • keyword_list (required for a relationship property but otherwise optional ) is a comma-separated list of keywords that further define the property.

    See Property Syntax and Keywords for a complete keyword list.

    If this list is omitted, also omit the square brackets.


Relationships are not supported for sharded classes.


/// Person's Social Security number. 
Property SSN As %String(PATTERN = "3N1""-""2N1""-""4N") [ Required  ]; 

See Also

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