What potential issue could arise when trying to sum up values in a PHP loop?

One potential issue that could arise when summing up values in a PHP loop is variable scoping. If the variable used to store the sum is defined inside the loop, it will be reset to its initial value in each iteration, resulting in an incorrect sum. To solve this issue, the sum variable should be defined outside the loop so that its value persists across iterations.

// Define the sum variable outside the loop
$sum = 0;

// Loop through an array of values and sum them up
$values = [1, 2, 3, 4, 5];
foreach ($values as $value) {
    $sum += $value;
}

// Output the final sum
echo "The sum of the values is: $sum";