Question

Possible Duplicate:
How do I deep copy a DateTime object?
Error in adding to 2d array or looping through 2d array

So my code is:

    while ($end <= $to){
        $currentDates = array("from" => $start, "to"=>$end);
        $allDates[] = $currentDates;
        echo '<br>', var_dump($allDates);
        unset($currentDates);
        $start->add($intervalObj);
        $end->add($intervalObj);
    }

But every time $currentDates is added to $allDates it adds a position to $allDates like I expect but it also overwrites all the previous array positions with the current values of $currentDates.

This is the result of the var_dump in the loop

array(1) { [0]=> array(2) { ["from"]=> object(DateTime)#6 (3) { ["date"]=> string(19) "2012-10-10 00:00:00" ["timezone_type"]=> int(3) ["timezone"]=> string(16) "America/New_York" } ["to"]=> object(DateTime)#7 (3) { ["date"]=> string(19) "2012-10-11 00:00:00" ["timezone_type"]=> int(3) ["timezone"]=> string(16) "America/New_York" } } } 

array(2) { [0]=> array(2) { ["from"]=> object(DateTime)#6 (3) { ["date"]=> string(19) "2012-10-11 00:00:00" ["timezone_type"]=> int(3) ["timezone"]=> string(16) "America/New_York" } ["to"]=> object(DateTime)#7 (3) { ["date"]=> string(19) "2012-10-12 00:00:00" ["timezone_type"]=> int(3) ["timezone"]=> string(16) "America/New_York" } } [1]=> array(2) { ["from"]=> object(DateTime)#6 (3) { ["date"]=> string(19) "2012-10-11 00:00:00" ["timezone_type"]=> int(3) ["timezone"]=> string(16) "America/New_York" } ["to"]=> object(DateTime)#7 (3) { ["date"]=> string(19) "2012-10-12 00:00:00" ["timezone_type"]=> int(3) ["timezone"]=> string(16) "America/New_York" } } } 

array(3) { [0]=> array(2) { ["from"]=> object(DateTime)#6 (3) { ["date"]=> string(19) "2012-10-12 00:00:00" ["timezone_type"]=> int(3) ["timezone"]=> string(16) "America/New_York" } ["to"]=> object(DateTime)#7 (3) { ["date"]=> string(19) "2012-10-13 00:00:00" ["timezone_type"]=> int(3) ["timezone"]=> string(16) "America/New_York" } } [1]=> array(2) { ["from"]=> object(DateTime)#6 (3) { ["date"]=> string(19) "2012-10-12 00:00:00" ["timezone_type"]=> int(3) ["timezone"]=> string(16) "America/New_York" } ["to"]=> object(DateTime)#7 (3) { ["date"]=> string(19) "2012-10-13 00:00:00" ["timezone_type"]=> int(3) ["timezone"]=> string(16) "America/New_York" } } [2]=> array(2) { ["from"]=> object(DateTime)#6 (3) { ["date"]=> string(19) "2012-10-12 00:00:00" ["timezone_type"]=> int(3) ["timezone"]=> string(16) "America/New_York" } ["to"]=> object(DateTime)#7 (3) { ["date"]=> string(19) "2012-10-13 00:00:00" ["timezone_type"]=> int(3) ["timezone"]=> string(16) "America/New_York" } } } 

Answer 1

$start and $end are objects, which are always assigned by reference. You need to create new, distinct objects. See How do I deep copy a DateTime object? on how to do this.