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.\" -*- mode: troff; coding: utf-8 -*-
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.\" ========================================================================
.\"
.IX Title "vars 3perl"
.TH vars 3perl 2024-05-30 "perl v5.38.2" "Perl Programmers Reference Guide"
.\" For nroff, turn off justification.  Always turn off hyphenation; it makes
.\" way too many mistakes in technical documents.
.if n .ad l
.nh
.SH NAME
vars \- Perl pragma to predeclare global variable names
.SH SYNOPSIS
.IX Header "SYNOPSIS"
.Vb 1
\&    use vars qw($frob @mung %seen);
.Ve
.SH DESCRIPTION
.IX Header "DESCRIPTION"
NOTE: For use with variables in the current package for a single scope, the
functionality provided by this pragma has been superseded by \f(CW\*(C`our\*(C'\fR
declarations, available in Perl v5.6.0 or later, and use of this pragma is
discouraged.  See "our" in perlfunc.
.PP
This pragma will predeclare all the variables whose names are
in the list, allowing you to use them under \f(CW\*(C`use strict\*(C'\fR, and
disabling any typo warnings for them.
.PP
Unlike pragmas that affect the \f(CW$^H\fR hints variable, the \f(CW\*(C`use vars\*(C'\fR and
\&\f(CW\*(C`use subs\*(C'\fR declarations are not lexically scoped to the block they appear
in: they affect
the entire package in which they appear.  It is not possible to rescind these
declarations with \f(CW\*(C`no vars\*(C'\fR or \f(CW\*(C`no subs\*(C'\fR.
.PP
Packages such as the \fBAutoLoader\fR and \fBSelfLoader\fR that delay
loading of subroutines within packages can create problems with
package lexicals defined using \f(CWmy()\fR. While the \fBvars\fR pragma
cannot duplicate the effect of package lexicals (total transparency
outside of the package), it can act as an acceptable substitute by
pre-declaring global symbols, ensuring their availability to the
later-loaded routines.
.PP
See "Pragmatic Modules" in perlmodlib.