Brief introductory presentation, for the Lambdas Hackday at DevoxxUK

1. Higher Order Lab
Richard Warburton
Stuart Marks
Maurice Naftalin
Graham Allan
John Oliver

2. Why are we here?
● Learn about lambda expressions and
collections
● Feedback on the new API
● Have fun

3. What's on the USB Stick?
● OpenJDK binaries with lambda support
○ Windows
○ Mac
○ Linux
● Javadoc for the new API
● IDEs with Support
○ Idea
○ Netbeans

4. Expectations
● You have a laptop
○ or a friend with a laptop!
● You've been to a lambdas talk ...
○ "Lambdas and Collections in Java 8"
○ "Accelerated Lambda Programming"
● ... or you know the basics already

5. Who's Who
Instructors: put up your hands!

6. What should we focus on
● At first just write the basics
● Revamped collections methods
○ flatMap()
○ reduce()
● Collect Changes:
○ into(new ArrayList<>()) => collect(toList())
○ groupBy(classifier) => collect(groupingBy(classifier))

7. Exercise Ideas:
● Sort a list of strings alphabetically within
length.
● Count number of words in a document
○ http://www.gutenberg.org
● Implement 'sum' and 'average' of command-
line arguments
● Count word frequency in a document
○ maybe without loading the entire document into
memory?
● Feedback @ bit.ly/14iINWi
● github.com/AdoptOpenJDK/Lambdas

8. Any Questions?
Feedback @ bit.ly/14iINWi
github.com/AdoptOpenJDK/Lambdas