You can't run without walking first. If you've programmed before, you probably won't need to be told what a variable is, and one look at a function declaration and you'll understand what that's all about too. Even if this applies to you, you'll still want to read this chapter because some properties of the language are quite distinct from those of Java, C, Perl, or C#. If you are new to programming or are seeing some of these building block concepts for the first time, not to worry. This chapter introduces all the language fundamentals as straightforwardly as possible. Soon they'll be second nature to you.
I'll begin our discussion of the language with a broad overview of the most basic characteristics of the language.
A Dynamic Language
Eval: An evaluation expression is something that allows us to introduce new source code to the program at runtime. By enclosing ...