Preface

Back in 1998 when I was eight years old, I picked up my first book on computing—on JavaScript and HTML. Little did I know that opening that book would transform my life by exposing me to programming languages and the amazing things I could do with them. I was hooked. Every so often, I still find a new programming language feature that revives this excitement because it enables me to write clearer, more concise code in half the time. I hope that the new ideas in Java 8, Java 9, and Java 10, incorporated from functional programming and explored in this book, inspire you in the same way.

So, you may wonder, how did this book—and its second edition—come about?

Well, back in 2011, Brian Goetz (the Java Language Architect at Oracle) was sharing various proposals to add lambda expressions to Java, with the aim of getting the community involved. These rekindled my excitement, and I started to evangelize the ideas, organizing Java 8 workshops at various developer conferences and giving lectures to students at the University of Cambridge.