Set Perl Variables

Often, you only need to use a variable to store a single text or numeric value. Such variables are referred to as scalar variables in Perl.

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Scalar Variable Names

Perl scalar variables are prefixed by the dollar sign ($) character. In addition, all Perl variable names must follow these rules:

Variable names must contain only letters (a-z, A-Z), underscores (_), and numeric digits (0-9).
The first character of a variable name must be a letter (a-z, A-Z) or underscore (_).
Variable names are case-sensitive, so myvariable is not the same as MyVariable.

Some variable names are used by WebAssign. These variables are listed in the documentation.

In an <EQN> or <eqn> tag, include an assignment statement like the following:
```
$variable = value;
```
where variable is the variable name and value is the value to be assigned. The value can be either a single value or a Perl expression that results in a value.

Examples The following example variable assignment statements should be inside an <EQN> or <eqn> tag. # set $radius equal to 5 $radius = 5; # calculate the $diameter $diameter = $radius * 2; # use the predefined variable $pi $circumference = $diameter * $pi; # use ** for exponentiation $area = $pi * $radius ** 2; # use quotes to enclose a text value $message1 = 'The radius is '; # concatenate strings as text with the period (.) $message2 = $message1. $radius; # in double quotes, the value of a variable is substituted $message3 = "The diameter is $diameter.";