First a caution: Perl is a weakly typed language. That can be a plus or a minus.

There are three data types in perl

• Scalars
• Arrays of Scalars
• Hashes of Scalars (Associative Arrays)

Scalars are known as a singular context while arrays and hashes are known as a plural context.

$myvar = "Hello World!"
print "$myvar " $myvar = "Hello World!"
$myvar = 3.14159
print "$myvar " 3.14159

Scalar variables are singular or individual variables. They can represent strings or numbers becasue, once again, Perl is weakly typed. A Scalar variable is preceded with a $ i.e. a capitol 4.

In the world of Perl a null value of the Scalar variety is an empty string, a string with a zero i.e. 0 or the value zero i.e. 0. Internally Perl manages the data type.

Using a scalar data type the actual type can be switched on the fly i.e. the type can be switched from string to integer.