alvin's blog

Summary: How to properly use the Scala Option/Some/None idiom to initialize empty var fields -- and specifically how not to use null values for the same purpose.

When you get started in the Scala world, you quickly learn that null values are a bad thing. Scala makes it easy to replace null values with something better, and that something better is what I call the Option/Some/None pattern (or idiom).

Scala List FAQ: Can you share some Scala List class examples?

The Scala List class may be the most commonly used data structure in Scala applications. Therefore, it's very helpful to know how create lists, merge lists, select items from lists, operate on each element in a list, and so on.

In this tutorial, I'll try to share examples of the most common List operations (methods).

Scala collections FAQ: Can you share an example that shows how to get the max or min value from a collection using the Scala reduceLeft collections method?

I don't have much time today, but sure, here's a quick example. The following code will determine which student has the max (top/high) score:

Summary: A discussion of Scala type annotations and type ascription.

While Scala normally determines the type you want to use automatically, such as this Int:

scala> val x = 1
x: Int = 1

there may be times you want to control the type, such as if you want a Byte, Short, Long, Double, Float, etc. In these cases you can annotate your type when you create it, like this:

Scala FAQ: Can you share an example of how to create an implicit class in Scala 2.10?

Sure. As your question implies, the implicit class functionality changed in Scala 2.10, so let's take a look at the new syntax.