#!/usr/bin/perl

$foo = 42;

sub func {
    print "$foo\n";
}

{   # new local scope
    
    my $foo    = 99;  # lexical variable, statically scoped
    func();           # -> 42
}

{   # new local scope
    
    local $foo = 99;  # package variable, dynamically scoped
    func();           # -> 99
}