Strings are scalar values and are written as text enclosed within single quotes, like so:

'This is a string in single quotes.'

or double quotes, such as:

"This is a string in double quotes."

A single-quoted string prints out exactly as written. With double quotes, you can include a variable in the string, and its value will be inserted or "interpolated." You can also include commands such as to represent a newline (see Table B-3):

$aside = '(or so they say)';
$declaration = "Misery
 $aside 
loves company.";
print $declaration;

This snippet prints out:

Misery 
 (or so they say) 
loves company.

Numbers are scalar values that can be:

Complex (or imaginary) numbers, such as 3 + i, and fractions (or ratios, or rational numbers), such as 1/3, can be a little tricky. Perl can handle fractions but converts them internally to floating-point numbers, which can make certain operations go wrong (Perl is not alone among computer languages in this regard.):

if ( 10/3  == ( (1/3) * 10 ) {
	print "Success!";
}else {
	print "Failure!";
}

This prints:

Failure!

To properly handle rational arithmetic with fractions, complex numbers, or many other mathematical constructs, there are mathematics modules available, which aren't covered here.

Scalar values can be stored in scalar variables. A scalar variable is indicated with a $ before the variable's name. The name begins with a letter or underscore and can have any number of letters, underscores, or digits. A digit, however, can't be the first character in a variable name. Here are some examples of legal names of scalar variables:

$Var
$var_1

Here are some improper names for scalar variables:

$1var
$var!iable

Names are case sensitive: $dna is different from $DNA.

These rules for making proper variable names (apart from the beginning $) also hold for the names of array and hash variables and for subroutine names.

A scalar variable may hold any type of scalar value mentioned previously, such as strings or the different types of numbers.