array_merge() How can I add a 'range' of an array name - php

Question

I have a $nr variable that as the number of arrays with the same name that i created in a previous function, something like this:
$var = 'sorteios_'.$nr;
$$var = array($sorteio_id);
I have it in a While function so it was created something like 3 arrays with the names:
$sorteios_1 , $sorteios_2 , $sorteios_3
And i want to add them inside an array_merge, so i have to use the $nr that says how many arrays with the same name were created.
$nr = 3;
i want that the final result looks something like this.
$result = array_merge($sorteios_1, $sorteios_2, $sorteios_3);
That's the whole function if you want to check it (it's not complete because of the problem i'm having):
function check_sorteios(){
global $db;
$id = $_SESSION['userid'];
$query1 = "SELECT * FROM sorteios WHERE userid = $id";
$result1 = $db->query($query1);
$count = $result1->rowCount();
if ($count == 0){ $sorteios = 0; echo "sem sorteios";}
else{
$numero = 0;
$sorteios = 0;
$nr = 0;
while($row1 = $result1->fetch()){
if ( $numero == $count ){ return 0;}
$numero++;
$sorteio_id = $row1['id'];
$query2 = "SELECT * FROM productos WHERE id = $sorteio_id";
$result2 = $db->query($query2);
while($row2 = $result2->fetch()){
$data = $row2['data'];
$titulo = $row2['titulo'];
if (strtotime($data) > time()){
if(!isset($$sorteio_id)){
$$sorteio_id = 1;
}
$nr++;
$var = 'sorteios_'.$nr;
$$var = array($sorteio_id);
}
}
}
}
$result = array_merge($sorteios_1, $sorteios_2, $sorteios_3);
$occurences = array_count_values($result);
print_r($occurences);
}

Answer 1

You could try to create a string containing the code executing array_merge of all your arrays and then pass it to the eval function (http://it1.php.net/manual/it/function.eval.php)...
Something like this:
$str="\$result=array_merge(";
for($i=1;$i<=$nr;$i++){
$str.="\$sorteios_$i,";
}
$str=substr($str,0,-1);
$str.=");";
eval($str);
Then in $result you have what you need.

Answer 2

Is there a reason you can't recursively merge?
if ($nr > 0) {
$result = $sorteios_1;
for ($i = 2; $i <= $nr; ++$i) {
$result = array_merge($result, ${'sorteios_'.$i});
}
} else {
// you might want to handle this case differently
$result = array();
}