Line 1 is the header comment. Lines 2 and 3 are comments, not executable lines
of code. Line 4 reads a line of input. Line 5 writes the line of input on your screen.
End-of-Day Q& A and Workshop
Each day ends with a Q&A section containing answers to common questions relating to
that day's material. There also is a Workshop at the end of each day that consists of
quiz questions and programming exercises. The exercises often include BUG BUSTER
exercises that help you spot some of the common bugs that crop up in Perl programs. The
answers to these quiz questions as well as sample solutions for the exercises are
presented in Appendix A, "Answers."
Conventions Used in This Book
This book uses different typefaces to help you differentiate between Perl code and
regular English, and also to help you identify important concepts.
l Actual Perl code is typeset in a special monospace font. You'll see this font used in
listings and the Input-Output examples, as well as in code snippets. In the
explanations of Perl features, commands, filenames, statements, variables, and
any text you see on the screen also are typeset in this font.
l Command input and anything that you are supposed to enter appears in a bold
monospace font. You'll see this mainly in the Input-Output examples.
l Placeholders in syntax descriptions appear in an italic monospace font. Replace
the placeholder with the actual filename, parameter, or whatever element it
represents.
l Italics highlight technical terms when they first appear in the text and are
sometimes used to emphasize important points.
What You'll Learn in 21 Days
In your first week of learning Perl, you'll learn enough of the basics of Perl to write
many useful Perl programs. Here's a summary of what you'll learn in Week 1:
Day 1, "Getting Started," tells you how to get Perl, how to run Perl
programs, and how to read from your keyboard and write to your screen.
Day 2, "Basic Operators and Control Flow," teaches you about simple
arithmetic, how to assign a value to a scalar variable, and how to control
execution using conditional statements.