#!/usr/bin/perl
use warnings;
use strict;
use Data::Dumper;

my $questions = {
    1 => { foo => 'bar' },
    2 => { foo => 'bar' },
    3 => { foo => 'bar' }
};

print "(before):\n",Dumper($questions),"\n";

for (1 .. 4) {
    my $foo = $questions->{$_}{foo} || "daklfjsdalk";
}

print "(after): \n",Dumper($questions), "\n";