Splitting a Associative Array Based off if Condition of Value - php

Question

I'm combining an array based off a MySQL Query:
$newskus = array();
$newqtys = array();
$sql1 = $db->query("//QUERY//");
while($row = $sql1->fetch_assoc()) {
$newskus[] = $row['SKU'];
$newqtys[] = $row['Quantity'];
}
$newskusandqtys = array_combine($newskus, $newqtys);
This gives me an associative array like so:
Array
(
[Product 1] => -1
[Product 2] => 0
[Product 3] => 3
)
I'm looking to split this array based off the condition of the integer value.
That is, if the value is above 0, it'll put the contents into a variable $newqtysabovezero
Ending with an expected output of
Array
(
[Product 3] => 3
)
And the other way around, if the value is greater than or equal to 0, put this into an array variable $newqtysbelowzero with an expected output of
Array
(
[Product 1] => -1
[Product 2] => 0
)
I'm able to do this with a numerical array, but it of course is not passing the key:
foreach( $newqtys as $item ) {
if ( $item > '0' ) {
$newqtysabovezero[] = $item;
} elseif ( $item <= '0') {
$newqtysbelowzero[] = $item;
}
}
How would I modify this to get my expected output?

Answer 1

Here is one way:
foreach( $newqtys as $key => $item ) {
if ( $item > '0' ) {
$newqtysabovezero[$key] = $item;
} elseif ( $item <= '0') {
$newqtysbelowzero[$key] = $item;
}
}
And here is a method using array_filter():
$in = array(
'Product 1' => -1,
'Product 2' => 0,
'Product 3' => 3
);
function at_and_below($v) {
return $v <= 0;
}
function above($v) {
return $v > 0;
}
$newqtysabovezero = array_filter($in, 'above');
$newqtysbelowzero = array_filter($in, 'at_and_below');

Answer 2

At first, to get all values from the 'Quantity' field as integers you should cast them to integer type:
...
while($row = $sql1->fetch_assoc()) {
$newskus[] = $row['SKU'];
$newqtys[] = (int) $row['Quantity'];
}
$newskusandqtys = array_combine($newskus, $newqtys);
Then, you can easily separate values which are greater than OR equal/less than 0:
foreach (newskusandqtys as $k => $item) {
if ($item > 0) {
$newqtysabovezero[$k] = $item;
} else {
$newqtysbelowzero[$k] = $item;
}
}

Answer 3

You can skip the array_combine part, and just read the values into the final arrays as you fetch them.
while($row = $sql1->fetch_assoc()) {
if ($row['Quantity'] > 0) {
$newqtysabovezero[$row['SKU']] = $row['Quantity'];
} else {
$newqtysbelowzero[$row['SKU']] = $row['Quantity'];
}
}