© Toby Weston 2018

Toby Weston, Scala for Java Developers, https://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 ...

Get Scala for Java Developers: A Practical Primer now with O’Reilly online learning.

O’Reilly members experience live online training, plus books, videos, and digital content from 200+ publishers.