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InterviewSolution
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What are traits? What problem do they solve? |
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Answer» Traits are a mechanism for code reuse in single inheritance languages such as PHP. A Trait is intended to reduce some limitations of single inheritance by enabling a developer to reuse sets of methods freely in several independent classes living in different class hierarchies. The semantics of the combination of Traits and classes are defined in a way that reduces COMPLEXITY and AVOIDS the typical problems associated with multiple inheritance and Mixins. A Trait is similar to a class, but only intended to group functionality in a fine-grained and consistent way. It is not possible to instantiate a Trait on its own. It is an addition to traditional inheritance and ENABLES HORIZONTAL composition of behaviour; that is, the application of class members without requiring inheritance. <?php trait Hello { function sayHello() { echo "Hello"; } } trait World { function sayWorld() { echo "World"; } } class MyWorld { use Hello, World; } $world = NEW MyWorld(); echo $world->sayHello() . " " . $world->sayWorld(); //Hello World |
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