I'm trying to compare Advanced Custom Fields data from users with certain post data. Basically I have a user "radio" field (with a single value) where they can select between operating systems (such as Windows, Linux...). Depending on the type, they also can select the specific OS-version (as Windows 10 on a other field). I have also the post field where I can select multiple OS-versions (in my case which are supported by the game). For my example, the fields and their saved values:

  • User OS type: "windows"
  • User OS version: "10"
  • Post multi select os: "array( 'windows-7','mac-os-10.07','linux-ubunto-16.04')"

So now to check if the user OS supports the the post OS - First I would check if the user has generally installt the right os. Which could be done with this code:

$field_os = array('windows-7','mac-os-10.07','linux-ubunto-16.04');
$user_os_type = "windows";

if (strpos($field_os, $user_os_type) !== false) {
echo "It turns true because it found the word 'windows' in the array";

But in the second step I also have to check if the users the right os-version. This a litle bit tricky because: In this example the required os version is at least "windows-7", so I would be fine with os version: "10". But you see I have to filter the right os type from the array and than to remove the prefix "windows-" from it. So that I can compare the numbers like that:

$value = '10'; if($value >=7) {
echo "You have the right windows version";


The question is, how to find this string $user_os_type = "windows" in a ACF multi select field and store the similar match (which should be in this case "windows-7") in a variable.


I'm using this code now because the other one dosen't search as it should. It only worked if 'windows-7' is at the first place.

$input      = $user_os_type;            // search for this string
$words      = $os_array['value'];   // word array as source of comparison

$shortest   = -1;

foreach ($words as $word) { $lev = levenshtein($input, $word);
if ($lev == 0) { $match = $word; $shortest = 0; break; }
if ($lev <= $shortest || $shortest < 0) {

$match_os  = $word; $match_os = preg_replace('/[^0-9\.]/','',$match_os);
$shortest   = $lev; 
} }
  • Welcome to WPSE. You should reword your post so there is an actual question here. You have provided lots of information but this is a Q&A format site. Ask a single, clear question if you want a good, useful answer.
    – jdm2112
    Oct 26, 2016 at 20:34

1 Answer 1


There is a PHP function: preg_grep which accepts $pattern and $input as a parameters and returns you an array of matches. If you want to get first match just assign it to variable, e.x.:

$field_os = array('windows-7','mac-os-10.07','linux-ubunto-16.04');
$user_os_type = "windows";

$matches = preg_grep("/" . $user_os_type . "/", $field_os);


 array(1) {
  string(9) "windows-7"


$first_match = $matches[0];

echo $first_match; // Prints: windows-7

For more information visit this link: http://php.net/manual/en/function.preg-grep.php

  • Ok this works, if word array is structured like this $field_os = array('windows-7','mac-os-10.07','linux-ubunto-16.04');. Now I have problems to get AFC multi select field in this format. I've tried to do it like this: $os_array = get_sub_field_object('game_requirements_os'); ob_start(); foreach($os_array['value'] as $value): echo "'" .$value. "',"; endforeach; $field_os_words = ob_get_clean(); but the $first_match does echo the whole string now.
    – Game Unity
    Oct 27, 2016 at 11:46
  • I figured it out by my self: $field_os = $os_array['value']; does return the values. :)
    – Game Unity
    Oct 27, 2016 at 14:03
  • Nice to know that :) I'm glad that I put you on the right way Oct 27, 2016 at 14:11

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