What is the common issue with handling null values in PHP arrays?

Handling null values in PHP arrays can lead to unexpected behavior, especially when trying to access or manipulate those values. One common issue is that PHP treats null values as empty values, which can cause confusion when trying to distinguish between a null value and an empty string or zero. To solve this issue, it is recommended to explicitly check for null values using the `is_null()` function before performing any operations on the array element.

$array = [1, null, 3, 4, null];

foreach ($array as $value) {
    if (is_null($value)) {
        // Handle null value
        echo "Null value found\n";
    } else {
        // Handle non-null value
        echo "Value: $value\n";
    }
}