php，在sql结果数组中创建一个新属性

Question

The following code keeps returning the error

Warning: Attempt to assign property of non-object

This happens during the line $a->tomorrowDate = array("dateTomorrow" => $invoiceNextDay);

foreach ($resultInvoices as &$a) {
                $invoiceDate = date_create_from_format('d/m/Y', $a['date']);
                $invoiceNextDay = $invoiceDate->modify('+1 day');
                $invoiceNextDay->format('Ymd');
                $a->tomorrowDate = array("dateTomorrow" => $invoiceNextDay);
                $a['date']=$invoiceDate->format('Ymd');
            }

What is wrong with that line?

Answer 1

I found out my issue.

 foreach ($resultInvoices as &$a) {
                $invoiceDate = date_create_from_format('d/m/Y', $a['date']);
                $a['date']=$invoiceDate->format('Ymd');
                $invoiceNextDay = $invoiceDate->modify('+1 day');
                $invoiceNextDay->format('Ymd');
                $a['tomorrowDate'] = $invoiceNextDay;
            }

Essentially, what I tried before was for objects, whilst now, its specific to arrays. $a['tomorrowDate'] = $invoiceNextDay; This will create a new element in the array with attribute tomorrowDate and then assign it the value.