Somewhere in mid-2017 I started working on a Kotlin programming book, but then I had to get away from it to work on other things. When I got back to it recently I looked around and felt like the world didn’t need another “Introduction to Kotlin” book — there are a couple of good ones out there, including Kotlin in Action, and the kotlinlang.org documentation is excellent — so I decided to ditch the project completely.Back to top
Kotlin Quick Reference
But then when I started writing some Kotlin code again I realized that what I really needed was a quick reference. I didn’t want to have to dig through a tutorial book or website to find what I need, I just wanted something like a large cheat sheet where I could quickly find the Kotlin syntax and examples for whatever I was working on at that moment. So I decided to strip down what I had already written and create both a book and a Kotlin Quick Reference website.
Summary: This page is a printf formatting cheat sheet. I originally created this cheat sheet for my own purposes, and then thought I would share it here.
A cool thing about the printf formatting syntax is that the specifiers you can use are very similar, if not identical, between several different languages, including C, C++, Java, Perl, Ruby, and others, so your knowledge is reusable, which is a good thing.
The Scala List class as an immutable, linear, linked-list class. It’s very efficient when it makes sense for your algorithms to (a) prepend all new elements, (b) work with it in terms of its head and tail elements, and (c) use functional methods that traverse the list from beginning to end, such as
Important note about Seq, IndexedSeq, and LinearSeq
As an important note, I use
Seq in the following examples to keep things simple, but in your code you should be more precise and use
LinearSeq where appropriate. As the
Seq class Scaladoc states:
After I sold Mission Data in 2007, I also sold most of my belongings and drove to Alaska, a state I fell in love with during several vacations many years ago. As a result of that moving process, I sold over 400 books, keeping only the 100 or so “best” books that would fit in my car.
Forced to think about keeping only ~100 books, I learned that my favorite business books are: