Chapter 2. Scalar Data


In English, as in many other spoken languages, you're used to distinguishing between singular and plural. As a computer language designed by a human linguist, Perl is similar. As a general rule, when Perl has just one of something, that's a scalar.[*] A scalar is the simplest kind of data that Perl manipulates. Most scalars are a number (like 255 or 3.25e20) or a string of characters (like hello[] or the Gettysburg Address). Though you may think of numbers and strings as different things, Perl uses them nearly interchangeably.

[] If you have been using other programming languages, you may think of hello as a collection of five characters, rather than as a single thing. But in Perl, a string is a single scalar value. Of course, you can access the individual characters when you need to; youll see how to do that in later chapters.

A scalar value can be acted on with operators (such as addition or concatenation), generally yielding a scalar result. A scalar value can be stored into a scalar variable. Scalars can be read from files and devices, and can be written out as well.



Learning Perl
Learning Perl, 5th Edition
ISBN: 0596520107
EAN: 2147483647
Year: 2003
Pages: 232

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