SAMS Teach Yourself Perl in 24 Hours THIRD EDITION

Scalar Variables

To store scalar data in Perl, you must use a scalar variable. In Perl, you indicate a scalar variable with a dollar sign followed by the name of the variable. The following are some examples:

$a
$total
$Date
$serial_number
$cat450

The dollar sign—called a type identifier—indicates to Perl that the variable contains scalar data. Other variable types (hashes and arrays) use a different identifier or no identifier at all (filehandles). Variable names in Perl—whether for hashes, arrays, filehandles, or scalars—must conform to the following rules:

• Variable names can contain alphabetic (a to z, A to Z) characters, numbers, or an underscore character (_) after the type identifier. The first character of a variable name can't be a ...