PHP add Date Function for specified variable

Question

How to add a date with DateInterval for specified variable?

<?php
$begin = new DateTime('2010-01-01 08:00');
$end = new DateTime( '2010-01-05 20:00');

$interval = new DateInterval('P1D');
$period = new DatePeriod($begin, $interval, $end);

foreach ( $period as $dt ) {
  $tempBegin = $tempEnd = $dt;
  $tempEnd->add(new DateInterval('P1D'));

  echo $tempEnd->format( "Y-m-d H:i" ) . '<br/>';
  echo $tempBegin->format( "Y-m-d H:i" ) . '<br/>';
}

It will give result like this :

2010-01-02 08:00
2010-01-02 08:00
2010-01-03 08:00
2010-01-03 08:00
2010-01-04 08:00
2010-01-04 08:00
2010-01-05 08:00
2010-01-05 08:00
2010-01-06 08:00
2010-01-06 08:00

I want to add 1 day just for $tempBegin variable.

Answer 1

When you assign objects, you don't make copies. So the variables $tempBegin and $tempEnd both refer to the same object, and when you modify it with add() it modifies the object that both variables refer to.

You need to clone the object:

$tempBegin = $dt;
$tempEnd = clone $tempBegin;
$tempEnd->add(new DateInterval('P1D'));