PHP uses references in for-loop

Question

I am looping through a for-loop to fill an array with dates. With each iteration I want to increase the date variable by one day.

$myDate = date_create(date_default_timezone_get());
$myArr;
for ($i = 0; $i <= 1; $i++) {
    $myArr[$i] = $myDate;
    $myDate->modify('+1 day');
}

What it returns to me if the current date is 06-November-2021:

echo date_format($myArr[0], 'd.m.Y'); //08.11.2021
echo date_format($myArr[1], 'd.m.Y'); //08.11.2021

I would expect that it returns 06.11.2021 and 07.11.2021 but it seems it uses some kind of references instead of values in my array. Can someone explain?

In PHP, as in many other languages, objects are passed by reference. So you're adding and modifying the same object instance. Please check the [clone](https://www.php.net/manual/en/language.oop5.cloning.php) operator. — Álvaro González, Nov 06 '21 at 09:58
"seems it uses some kind of references" -- use https://www.php.net/manual/en/function.spl-object-id to find out yourself. — Ulrich Eckhardt, Nov 06 '21 at 10:37
I am not really used to PHP programming but I found this thread and thought this would count in general: https://stackoverflow.com/questions/879/are-php-variables-passed-by-value-or-by-reference — Julian, Nov 06 '21 at 10:58
If you don't need the date object anymore, you should format the date inside your loop and assign the formated string to your array. — Mujnoi Gyula Tamas, Nov 06 '21 at 11:02

score 2 · Accepted Answer · answered Nov 06 '21 at 09:48

you should create a new date and assign it to array try this

<?php
$myDate = date_create(date_default_timezone_get());
$myArr;
for ($i = 0; $i <= 4; $i++) {
    $myArr[$i] = date_create(date_format($myDate,'d.m.Y'));
    $myDate->modify('+1 day');
}

echo "<pre>";
print_r($myArr);
echo "</pre>";
?>

result

PHP uses references in for-loop

1 Answers1