Variable variables counted php - php

Question

I know the title isn't that good, BUT I really don't know how to describe it in one setence and I need help.
Currently I have this type of disastrous code that count every $type of product there is in the DB (I have 20-30 types, not 2 only):
$cong = 0;
$refr = 0;
if (mysqli_num_rows($result) > 0) {
while ($row = mysqli_fetch_assoc($result)) {
$arr[] = $row;
if ($arr[$t]['product_type'] == 'Congélateur') {
$cong += 1;
}
if ($arr[$t]['product_type'] == 'Réfrigérateur') {
$refr += 1;
}
$t++;
}
}
And I do stuff with it after. But I was disgusted to see that code, so I tried to minimize it, but I can't figure it out, I tried that:
<php?
$t = 0;
$type = array(
"cong" => "Congélateur",
"refr" => "Réfrigérateur",
);
extract($type, EXTR_PREFIX_SAME, "");
if (mysqli_num_rows($result) > 0) {
foreach ($type as $type_n => $type_m) {
$$type_n = 1;
while ($row = mysqli_fetch_assoc($result)) {
$arr[] = $row;
foreach ($type as $type_n2 => $type_m2) {
if ($arr[$t]['product_type'] == $type_m2) {
$$type_n++;
}
}
$t++;
}
echo $type_n . "=" . $$type_n . "<br>";
}
}
?>
Output:
cong=9
refr=1
What we should expect regarding the DB (In the database, there's 2 cong and 6 refr):
cong=2
refr=6
Any sugestion? Thank you!

Answer 1

You're really making this more complicated than it needs to be. Variable variables are almost never the solution and can always be replaced with an array.
The code you're working with makes no sense, why is it assigning $row to another array and then using a counter to access it? The answer you accepted includes 4 loops, one of them nested.
if (mysqli_num_rows($result) === 0) {
// always exit early rather than indent yourself to death
return false;
}
while ($row = mysqli_fetch_assoc($result)) {
$type = $row["product_type"];
$counts[$type] = ($counts[$type] ?? 0) + 1;
}
print_r($counts);
Demo: https://3v4l.org/8cuis#focus=7.3.28

Answer 2

Counters (which count the type names in your example) should be initialised to 0 not to 1.
You also need to increment $$type_n2 in DB read loop. I'd avoid variable variables if possible.
<php?
$t = 0;
$type = array(
"cong" => "Congélateur",
"refr" => "Réfrigérateur",
);
extract($type, EXTR_PREFIX_SAME, "");
if (mysqli_num_rows($result) > 0) {
foreach ($type as $type_n => $type_m) {
$$type_n = 0;
}
while ($row = mysqli_fetch_assoc($result)) {
$arr[] = $row;
foreach ($type as $type_n2 => $type_m2) {
if ($arr[$t]['product_type'] == $type_m2) {
$$type_n2++; // not $$type_n
}
}
$t++;
}
foreach ($type as $type_n => $type_m) {
echo $type_n . "=" . $$type_n . "<br>";
}
}
?>