Given an array of arrays, how can I replace all empty values with 0?

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开发者_如何转开发. 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 array_walk_recursive function, with a callback function that would replace null by 0.

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);

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

You could use this kind of code :

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

With the following callback functon :

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

Note that :

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

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;
}

From PHP7.4 and higher, you can use arrow function syntax to make iterated calls of intval() on each row. This is safe to use on your data because none of the input values will be damaged by unconditionally casting them to int type data.

Code: (Demo)

var_export(
    array_map(fn($row) => array_map('intval', $row), $myArray)
);