Tinkering with Perl

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Scalars

A scalar is a variable that can either refer to a number, or some text, which is called a string. A string is usually enclosed in quotes, like this:

"This is a string."

Note that the quotes are not actually part of the string; they are put around the string to tell when the string begins and ends.

You can give a variable almost any name that you can make from letters, numbers, and underscores ('_'). Furthermore, you must put a dollar sign ('$') before a scalar to tell Perl that it is a scalar.

In general, it is a good idea to have a variable name consist of a few words that describe what the variable tells you. There are a couple of ways people have of putting words together. (You have to do something to tell when one word ends and the next begins, because itishardtoreadwhenyoucan'tseparatewords.) One way is to capitalize the first letter of each word; another is to separate words using underscores ('_'). It doesn't matter which way you do it, but you should pick one way and stick with it. It is very important that you spell a variable exactly the same way every time you use it; otherwise, the computer will think you are using different variables. Here are some examples of good variable names:

$NumberOfTrucks
$AverageHeight
$PlayerName

Or, if you prefer underscores, then you can do it this way:

$number_of_trucks
$average_height
$player_name

In this book, I will always do it the first way.

Tinkering with Perl

Scalars

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