UseDefault (GenericNamedArraylist property)

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Flag indicating whether or not Item returns the Default value when name has no value (FloatNamedArraylist, NamedArraylist, and UnicodeNamedArraylist classes)

Flag is a ReadWrite property indicates whether an attempted retrieval of an item that is not in the FloatNamedArraylist, NamedArraylist, or UnicodeNamedArraylist should result in request cancellation of return the Default property value.


%currentBoolean = anyNal:UseDefault anyNal:UseDefault = newBoolean

Syntax terms

%currentBoolean A declared enumeration object of type Boolean into which the current value (True or False) will be returned.
anyNal A FloatNamedArraylist, NamedArraylist, or UnicodeNamedArraylist object.
newBoolean A boolean literal or declared enumeration, to set the new value of UseDefault property.

Usage Notes

  • UseDefault will return, or may be assigned, only the boolean values True or False. Its initial, default value is False.


Given the following fragment:

%nal is namedArraylist of string len 30 %nal = new %nal('Akron') = 'Rubber City' %nal('Atlanta') = 'The Athens of the South' %nal('Philadelphia') = 'City of Brotherly love' print %nal('Philadelphia') with '!' %nal:useDefault = true print %nal('Boston') with '!' %nal:useDefault = false print %nal('Boston') with '!'

The result is:

City of Brotherly love! ! *** 1 CANCELLING REQUEST: MSIR.0751: Class NamedArraylist, property Item: ItemNotPresent exception: item not present in line ...

Notice that the first print %nal('Boston') outputs the null string (the default value for the string len 30 item type) because of the preceding %nal:useDefault = true, but then when set to false the same item invocation cancels the request.

See also