To answer your first question: a namespace is the "space" in which identifiers corresponding to a program are stored. These identifiers include variable names, subroutine names, file handle names, and mostly anything that you can refer to by name in a Perl program (or in any other, the concept is not exclusive to Perl).

The main reason to be aware of namespaces is that you cannot have two things of the same type with the same name in the same namespace, but you can do that if they are in different namespaces. For example, each package in Perl defines a new namespace, which is why different packages can have variables with the same name and not have them conflict with each other. In perl, the fully qualified name of a variable or a subroutine is given by prepending its package name separated by two colons. So for example, if both packages A and B define a variable v, they are actually two different variables, with the full names $A::v and $B::v.

In reply to Re: basic conception? by ZZamboni
in thread basic conception? by yicstone

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