Perl CGI Happy Path: Creating Variables

Creating variables

• Constants (literals) are certainly important, but if that's all there was Perl would be a pretty boring place... nothing could ever change.
• Up to this point we have been looking only at Literals . Certainly important, but of limited utility for a dynamic program, as a literal can never change.
• A Perl Variable, like variables in other languages, is simply a symbolic representation of a storage location to be manipulated.
• That's the fancy way to say it. You can also think of a variable as a shoebox. You write a label on the side of the shoebox so you can tell that particular shoebox from all the other shoeboxes you may be using, and you can put a value into a shoebox to store safely for later use.
• Perl scalar variables begin with a $ symbol, followed with a letter, followed by more letters, digits, or underscores. Variable names are case sensitive.
• Example Perl Scalar Names
  • $Hello_There
  • $All4One
  • $x

• Remember Perl does not care if it is a numeric scalar, or a string scalar. This is very unusual compared to other languages, and it is remarkable how few problems it creates, and how many problems it solves. This is the kind of language your computer science professors warned you about...