Why Java 8 changed everything

Java 8 Course · lesson 1 of 16 · 3 min read

Java 8 was the biggest language shift since generics, and every release since builds on it.

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Key points

  • Released March 2014. Ten years on it is still the version most legacy code sits on.
  • Before 8, passing behaviour into a method meant writing an anonymous class - five lines of ceremony for one line of logic.
  • Java 8 made functions first-class. That single change unlocked streams, Optional and modern API design.
  • It also quietly fixed the JVM: PermGen was removed and a real date/time API finally shipped.
  • Understanding 8 is not optional history - it is the floor every later feature stands on.

Java 8 turned behaviour into something you can pass around, and the whole language followed.

Lambdas: the syntax that started it

This is a reading copy. The full lesson — with the visual explainer, the interactive lab and a Run button for the code — lives in the Java 8 Course course, and every lesson in it is listed on the Java 8 Course contents page.