Using preg_replace on an array

Question

I have a relatively large array of elements which I want to search for a string and replace any matches. I'm currently trying to do this using preg_replace and regular expressions:

preg_replace("/\d?\dIPT\.\w/", "IPT", $array);

I want to get all values which match either 00IPT.A or 0IPT.A (with 0 representing any numerical character and A representing any letter) and replace them with IPT. However, I'm getting array to string conversion notices. Is there any way to get preg_replace to accept an array data source? If not, is there any other way I could achieve this?

The documentation says that preg_replace should be able to accept array sources — this is the reason I'm asking.

The string or an array with strings to search and replace. If subject is an array, then the search and replace is performed on every entry of subject, and the return value is an array as well.

The array is multidimensional if that helps (has multiple arrays under one main array).

Answer 1

preg_replace doesn't modify in place. To permanently modify $array, you simply need to assign the result of preg_replace to it:

$array = preg_replace("/\d{1,2}IPT\.\w/", "IPT", $array);

works for me.

$array = array('00IPT.A', '0IPT.A');
$array = preg_replace("/\d{1,2}IPT\.\w/", "IPT", $array);
var_dump($array);
// output: array(2) { [0]=> string(3) "IPT" [1]=> string(3) "IPT" }

Note: the \d{1,2} means one or two digits.

If you want to do this to a two-dimensional array, you need to loop through the first dimension:

$array = array( array('00IPT.A', 'notmatch'), array('neither', '0IPT.A') );    
foreach ($array as &$row) {
    $row = preg_replace("/\d{1,2}IPT\.\w/", "IPT", $row);
}
var_dump($array);

output:

array(2) { 
    [0]=> array(2) { 
        [0]=> string(3) "IPT" 
        [1]=> string(8) "notmatch" 
    } 
    [1]=> &array(2) { 
        [0]=> string(7) "neither" 
        [1]=> string(3) "IPT" 
    } 
}

Note that you have to loop through each row by reference (&$row) otherwise the original array will not be modified.