Variables in Perl

Variables in Perl - module P301

Perl variables come in seven types. You should be familiar with scalars, lists and hashes before you start this module, but you've probably still got more to learn. And how about code variables, file handles and typeglobs?

This topic is presented on public course Perl for Larger Projects

Examples from our training material

danger	What variables have I used?
dele	delete, undef, defined and exists
fact	recursion in Perl
mkd2	Anonymous lists using [ and ]
mkpascal	Pascal's triangle; clever use of formatting
my2	scoping with "my"
pers	persistent my variable
phash	data munging - unpack, splice, regular expressions etc
ref1	References
ref2	Modifying values passed in to a subroutine
ref3	handling a list of lists element by element, by row, and as a whole
scal_type	ref function - what is in a scalar
scope	variable scope illustration
sfact	Beware of variable scope in recursive code
sfact1	Use of strict to flag scoping dangers
sfact3	Using package names to supress strict warnings
splitter	select and typeglobs for file handles - alternative to array of file handles
st	Accessing Perl's symbol tables
st2	Dumping out all variables defined
tgd	typeglobs - a package deal (one of everything!)
vbn	Soft References

Background information

Some modules are available for download as a sample of our material or under an Open Training Notes License for free download from http://www.training-notes.co.uk.

Topics covered in this module

Scalars, lists, hashes, code, file handles and typeglobs.
Symbol tables and accessing them.
Soft and hard references.
Undef and delete.
My and local scoping.
Strict.
References.
Multidimensional lists.
Dynamic creation of structures.
Anonymous data.

Complete learning

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