© Toby Weston 2018
Toby WestonScala for Java Developershttps://doi.org/10.1007/978-1-4842-3108-1_13

13. Generics

Toby Weston
(1)
London, UK
 
In this chapter we’ll look at generics or type parameterization or generic programming in Scala. We’ll look at the following:
  • Syntax for generics: defining types and methods.
  • Bounded types, extends and super.
  • Wildcards in both Java and Scala.
  • Covariance and contravariance.

Parametric Polymorphism

We talked briefly about subtype or inclusion polymorphism ; the idea that subtypes can be substituted to stand in for their super-types. These stand-ins can provide different behavior without changing the structure of your code. The types of polymorphism are:
  • Inclusion polymorphism (see Chapter 11, Inheritance).
  • Ad hoc ...

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