Lambda Expressions in Java 8 | Dr Dobb's

A lambda expression is a block of code with parameters.

Use a lambda expression whenever you want a block of code executed at a later point in time.

Lambda expressions can be converted to functional interfaces.

Lambda expressions can access effectively final variables from the enclosing scope.

Method and constructor references refer to methods or constructors without invoking them.

You can now add default and static methods to interfaces that provide concrete implementations.

You must resolve any conflicts between default methods from multiple interfaces.

You never specify the result type of a lambda expression. It is always inferred from context. 

Method References
button.setOnAction(System.out::println);
Arrays.sort(strings, String::compareToIgnoreCase)

Constructor References
Button[] buttons = stream.toArray(Button[]::new);

Static Methods in Interfaces

As of Java 8, you are allowed to add static methods to interfaces. There was never a technical reason why this should be outlawed: It simply seemed to be against the spirit of interfaces as abstract specifications.

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