Numeric and String Literals

  In this chapter, we willl take a look at some of the ways that Perl handles data. All computer programs use data in some way. Some use it to personalize the program. For example, a mail program might need to remember your name so that it can greet you upon starting. Another program-say one that searches your hard disk for files-might remember your last search parameters in case you want to perform the same search twice.

A literal is a value that is represented "as is" or hard-coded in your source code. When you see the four characters 45.5 in programs it really refers to a value of forty-five and a half. Perl uses four types of literals. Here is a quick glimpse at them:

• Numbers - This is the most basic data type.
• Strings - A string is a series of characters that are handled as one unit.
• Arrays - An array is a series of numbers and strings handled as a unit. You can also think of an array as a list.
• Associative Arrays - This is the most complicated data type. Think of it as a list in which every value has an associated lookup item.

Arrays will be discussed in Chapter 4 Numbers and strings will be discussed in the following sections.