Question:

Example array

$myArray[0] = array('23', null, '43', '12'); $myArray[1] = array(null, null, '53', '19'); $myArray[2] = array('12', '13', '14', null);

All nulls should be replaced with 0. I was hoping someone would have an efficient way of doing this, perhaps a built in PHP function that I am unaware of.

You could use the <a href="http://fr2.php.net/manual/en/function.array-walk-recursive.php" rel="nofollow"><strong>array_walk_recursive</strong></a> function, with a callback function that would replace null by 0.

<br /> For example, considering your array is declared this way :

$myArray[0] = array(23, null, 43, 12); $myArray[1] = array(null, null, 53, 19); $myArray[2] = array(12, 13, 14, null);

<em>Note : I supposed you made a typo, and your arrays are not containing only a string, but several sub-elements.</em>

<br /> You could use this kind of code :

array_walk_recursive($myArray, 'replacer'); var_dump($myArray);

<br /> With the following callback functon :

function replacer(& $item, $key) { if ($item === null) { $item = 0; } }

Note that :

<ul><li>the first parameter is passed by reference ! <ul><li>which means modifying it will modify the corresponding value in your array</li> </ul></li> <li>I'm using the === operator for the comparison</li> </ul>

<br /> And you'd get the following output :

array 0 => array 0 => int 23 1 => int 0 2 => int 43 3 => int 12 1 => array 0 => int 0 1 => int 0 2 => int 53 3 => int 19 2 => array 0 => int 12 1 => int 13 2 => int 14 3 => int 0

If the single quotation marks are unintentional, and the arrays have integers and null values:

for ($i = 0; $i < count($myArray); $i++) { if ($myArray[$i] == null) $myArray[$i] = 0; }