PHP function that calls itself always returns null

Question

I have searched, researched, cursed a lot and shouted at my computer screen repeatedly but nothing seems to work…

I have created the below function to query a mysql database against the current date. If the current date does not exist in the database, the previous days date is generated and the function calls itself again with the new date. This continues until a match is found at which point the function returns an array with the required data.

function getWeekNumber($dateToQuery) {
    $oneDay = 86400;
    $timestamp = $dateToQuery;
    $stringDate = date("d/m/y", $dateToQuery);

    include("inc/dbconx.php");
    try {
        $STH = $DBH->prepare("SELECT `Week_Commencing`,`Week_Number` FROM weeks WHERE `Week_Commencing` = ?");
        $STH->bindParam(1,$stringDate);
        $STH->execute();
    } catch (Exception $e) {
        echo "There was a problem retrieving data from the database";
        exit;
    }

    $result = $STH->fetch(PDO::FETCH_ASSOC);

    if ($result == FALSE) {
        $prevDay = $timestamp - $oneDay;
        getWeekNumber($prevDay);
    } else {
        $output = array("Week_Commencing" => $result['Week_Commencing'], "Week_Number" => $result['Week_Number']);
        var_dump($output);
        return $output;
    }
}

$weekNumber = getWeekNumber($serverTime);
var_dump($weekNumber);

Everything works and you will see where I have included var_dumps to check the results…

The var_dump within the else clause of the function outputs as expected:

array(2) {
    ["Week_Commencing"]=> string(8) "19/05/14"
    ["Week_Number"]=> string(1) "4"
}

However, when I call the function it always returns NULL.

Does anyone know why this is happening?

Thanks in advance

May I sugggest PAP - Professional Agressive Programming? Shouting the computer is only the entry level ... :) There is also ADD - Agression Driven Development. And there is a school of taught favoring Escalation over Exception handling. — hakre
– hakre, Commented May 25, 2014 at 20:03

deceze · Accepted Answer · 2014-05-25 20:00:32Z

5

return getWeekNumber($prevDay);
^^^^^^

The function is not magically going to return a value, even from a recursive call, without the return statement.

answered May 25, 2014 at 20:00

deceze♦

525k89 gold badges806 silver badges954 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

user3674344 Over a year ago

My life is now complete! Cheers buddy

user3130569 · Accepted Answer · 2014-05-25 19:57:19Z

0

The return statement is in the else block. It executes when $result is true. So the $result seems to be false. Always.

answered May 25, 2014 at 19:57

user3130569

1 Comment

deceze Over a year ago

In that case there would be no var_dump and eventually the script would die with a stack overflow.

Collectives™ on Stack Overflow

PHP function that calls itself always returns null

2 Answers 2

1 Comment

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

1 Comment

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related