Programming Scala

Chapter 2. Type Less, Do More

In This Chapter

We ended the previous chapter with a few “teaser” examples of Scala code. This chapter discusses uses of Scala that promote succinct, flexible code. We’ll discuss organization of files and packages, importing other types, variable declarations, miscellaneous syntax conventions, and a few other concepts. We’ll emphasize how the concise syntax of Scala helps you work better and faster.

Scala’s syntax is especially useful when writing scripts. Separate compile and run steps aren’t required for simple programs that have few dependencies on libraries outside of what Scala provides. You compile and run such programs in one shot with the scala command. If you’ve downloaded the example code for this book, many of the smaller examples can be run using the scala command, e.g., scala filename.scala. See the README.txt files in each chapter’s code examples for more details. See also Command-Line Tools for more information about using the scala command.

Semicolons

You may have already noticed that there were very few semicolons in the code examples in the previous chapter. You can use semicolons to separate statements and expressions, as in Java, C, PHP, and similar languages. In most cases, though, Scala behaves like many scripting languages in treating the end of the line as the end of a statement or an expression. When a statement or expression is too long for one line, Scala can usually infer when you are continuing on to the next line, as shown ...