Civil Engineering 82.562 -- The Perl Programming Language

Perl Glossary

Default Values

When a variable is used that has never been assigned a value, a default value is supplied. That default value is 0, 0.0, "" (null string), or empty array, depending on the context within which it is used.

Literal

A literal is a constant that you use in expressions in the program source code. For example, in the expression 'A+13', '13' is a literal (constant).

Newline

The newline character is a special character that, when printed, invariably causes the printer to advance to the start of a new line. I.E., a newline character typically ends every single line of output and often is used to separate lines in text files, as well. On unix machines, the newline character is almost always a single ASCII LF (linefeed); on DOS a newline is usually represented by the pair of ASCII characters CR LF (carriage return/line feed). But you are not supposed to know or care about this technical detail.

Variable Reference

The idea of variable extended a bit to also include elements of arrays. For example, if @arr is an array, then $arr[2] is a variable reference to one of its elements.