scala

Scala FAQ: Can you share some examples of the Scala for loop syntax?

Sure. I'm going to start with a comparison to Java for loops, because that's what I was just thinking about.

In Java you might write a for loop like this:

for (int i = 0; i < 10; i++) {
  System.out.println(i);
}

The equivalent for loop in Scala looks like this:

for (i <- 1 to 10) {
  println(i)
}

(The use of parentheses isn't necessary in either example, but most for loops will be longer.)

UPDATE: I originally posted this article in January, 2013, and it's now mid-February, 2013, and we're no longer looking for reviewers. I've only kept this page here so people won't get 404 errors.

OLD CONTENT:

Interested in being a reviewer for the Scala Cookbook?

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: