Documentation:OCLOperators nullValue: Difference between revisions

OCLOperators nullValue

Revision as of 21:11, 13 October 2023

A typed null value, used to assign a null value to an attribute, a variable or return null from a method.

someobject.someattribute := <Type>.nullValue

Do not use <Type>.nullValue to compare something to null, like this

vCurrent_UppdragTyp = Uppdragstyp.nullValue    -- WRONG

For comparing to null, use the operators .isNull or .notNull

This page was edited 84 days ago on 02/10/2024. What links here

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-A typed null value.
+A typed null value, used to assign a null value to an attribute, a variable or return null from a method.
+ someobject.someattribute := <Type>.nullValue
-<code>someobject.someattribute := <Type>.nullValue</code>
+Do '''not''' use <Type>.nullValue to compare something to null, like this
+ vCurrent_UppdragTyp = Uppdragstyp.nullValue    -- WRONG
+For comparing to null, use the operators [[OCLOperators isNull|.isNull]] or [[OCLOperators notNull|.notNull]]
 [[Category:OCL General Operators]]