In object-oriented programming, webehavior frequentlyis encounter behaviorsometimes shared bybetween classes,even if those classeswhich are not related to each other. For example, wemany mayunrelated wishclasses tomay allowhave many unrelated classesmethods to [[Serialization|serialize]] themselvesobjects to [[JSON]] for use in a [[Representational state transfer|REST API]]. Historically, there have been several approaches to solve this without duplicating the code in every class needing the behavior. PopularOther approaches have beeninclude [[multiple inheritance]] and [[mixin|mixins]], but these have drawbacks: the behavior of the code may unexpectedly change if you alter the order in which youthe inheritmixins orare "mixapplied in"is behavior.altered, Behavior can also unexpectedly changeor if you add new methods are added to yourthe parent classes or mixins.
Traits solve these problems by allowing classes to use the trait and get the desired behavior. If a class uses more than one trait, the order in which the traits are used does not matter. and theThe methods provided by the traits have direct access to the data of the class.▼
[[Delegation (computing)|Delegation]] is another approach, but if the object you're delegating to requires information from the class that contains said object, this can mean having to write additional code to guarantee you send that data at the appropriate time, thus complicating the code.
▲Traits solve these problems by allowing classes to use the trait and get the desired behavior. If a class uses more than one trait, the order in which the traits are used does not matter and the methods provided by the traits have direct access to the data of the class.
