Learning Java Lambdas

Chapter 3. Lambdas in Depth

In this section, we'll take a look at things in a little more detail and talk about some related topics, things like:

• Functional interfaces
• Method and constructor references
• Scope and effectively final variables
• Exception transparency
• The differences between lambdas and closures
• As we've talked about how lambdas aren't just syntactic sugar, we'll have a look at the bytecode lambdas produce

Functional interfaces

Java treats lambdas as an instance of an interface type. It formalizes this into something it calls functional interfaces. A functional interface is just an interface with a single method. Java calls the method a "functional method" but the name "single abstract method" or SAM is often used.

All the existing single method ...