review system with function in variable - php

Question

so basically I am trying to create a little thing where it outputs stars, based on the database saved rating integer. The problem is it does not seem to put the number I from the database, in the variable. Here is the code I used:
<?php
$productID = 100;
$con = mysqli_connect("localhost", "root", "", "example");
function connect()
{
$con = mysqli_connect("localhost", "root", "", "example");
// Check connection
if (mysqli_connect_errno()) {
echo "Failed to connect to MySQL: " . mysqli_connect_error();
} else {
return $con;
}
}
function getStars($con)
{
$productID = 100;
$sql = "SELECT rating
FROM reviews
-- JOIN stockitemstockgroups USING (StockItemID)
-- JOIN stockgroups USING (StockGroupID)
WHERE reviewID = '5'
";
$result = $con->query($sql);
if ($con && ($result->num_rows > 0)) {
// output data of each row
while ($row = $result->fetch_assoc()) {
echo $row["rating"];
}
} else {
echo "error";
}
}
$value = getStars($con);
echo $value;
for ($x = 1; $x <= $value; $x++) {
echo '<div class="rating"><span>★</span></div>';
}
?>

Answer 1

I'm having trouble finding a duplicate, though I'm sure this is one. You aren't returning anything from your function, so $value doesn't have a value.
function getStars($con)
{
$productID = 100;
$sql = "SELECT rating FROM reviews WHERE reviewID = 5";
$result = $con->query($sql);
if ($result && ($result->num_rows > 0)) {
// output data of first row
$row = $result->fetch_assoc();
return $row["rating"];
} else {
return false;
}
}
As a general rule, never echo from a function. Also, no need for a loop over what will presumably be a single result.