$ perl -E '
    my $x = { a => 1 };
    say $x->{a};
    {
        local $x->{a} = 2;
        say $x->{a};
    } 
    say $x->{a};
'
1
2
1

##</code><code>##

$ perl -E '
    my $x = { a => 1, b => 2 };
    say "@$x{qw{a b}}";
    {
        local @$x{qw{a b}} = (3,4);
        say "@$x{qw{a b}}";
    }
    say "@$x{qw{a b}}";
'
1 2
3 4
1 2

##</code><code>##

$ perl -E '
    my $x = { a => 1, b => 2 };
    say "@$x{qw{a b}}";
    {
        local @$x{qw{a b}} = (3,4);
        say "@$x{qw{a b}}";
        $x->{b} = "XYZ";
        say "@$x{qw{a b}}";
    }
    say "@$x{qw{a b}}";
'
1 2
3 4
3 XYZ
1 2