Add a variable to a class instance at runtime: Difference between revisions

=={{header|Smalltalk}}==

{{incorrect|Smalltalk|It extends the class (adds a new instance var and new method that will exists even in brand new future instances of that class), not only the particular instance. -- The description of the problem must be reworded then, as it

<lang smalltalk>Object subclass: #Monkey

instanceVariableNames: 'aVar'