In [[computer programming]], a '''trait''' is a concept used in [[object-oriented programming]], which represents a set of [[Method (computer programming)|methods]] that can be used to extend the functionality of a [[Class (computer science)|class]].<ref name="schaerli-ecoop-2003">{{cite journal | first1=Nathanael | last1=Schärli | first2=Stéphane | last2=Ducasse | first3=Oscar | last3=Nierstrasz | author-link3٧link3=Oscar Nierstrasz | first4=Andrew P. | last4=Black | url=http://scg.unibe.ch/archive/papers/Scha03aTraits.pdf | title=Traits: Composable Units of Behaviour | journal=Proceedings of the European Conference on Object-Oriented Programming (ECOOP). | series=Lecture Notes in Computer Science | volume=2743 | year=2003 | pages=248–274}}</ref><ref>{{cite journal | first1=Stéphane | last1=Ducasse | first2=Oscar | last2=Nierstrasz | first3=Nathanael | last3=Schärli | first4=Roel | last4=Wuyts | first5=Andrew P. | last5=Black | title=Traits: A mechanism for fine-grained reuse. | journal= ACM Transactions on Programming Languages and Systems | volume=28 | issue=2 | pages=331–388 | date=March 2006 | doi=10.1145/1119479.1119483}}</ref>
