Java AdvancedLesson 76Free preview

Java Generics

This lesson is part of Java · All levels

Summary

Generics makes classes, interfaces, and methods work with the newly specified data types when used. The advantage is the safety type and no manual casting is required. Java implements generics through erasure, so type information is deleted from the compiler after the compilation process.

Key points

Notation <T>; a class may have more than one parameter such as <K, V> on Map
Generic method written static void
Bounded type such as <T extends Number> limits the permissible type
Wildcard:? (all types),? extends T,? super T
Declarations of generic arrays are immediately prohibited; use ArrayList

Full lesson

Code examples and quizzes

Full lessons, code examples, and quizzes are available to subscribers. 5 questions.