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

Answer 1

your $array contains some further arrays. preg_replace works fine with arrays of strings, but not with arrays of arrays [of arrays...] of strings.

Answer 2

Your value does not sit in the array as a simple element but as a subset right? Like so?

array (
  array ('id' => 45, 'name' => 'peter', 'whatyouarelookingfor' => '5F'),
  array ('id' => 87, 'name' => 'susan', 'whatyouarelookingfor' => '8C'),
  array ('id' => 92, 'name' => 'frank', 'whatyouarelookingfor' => '9R')
)

if so:

<?php

foreach ($array as $key => $value) {
  $array[$key]['whatyouarelookingfor'] =  
    preg_replace("/\d?\dIPT\.\w/", "IPT", $value['whatyouarelookingfor']);
}

Or if more elements have this, just go broader:

<?php

foreach ($array as $key => $value) {
  $array[$key] =  
    preg_replace("/\d?\dIPT\.\w/", "IPT", $value);
}

Answer 3

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.