Надо чтобы функция возвращала строку?
$str = '2 3 4 5 6';
$res = preg_replace_callback( '#(\d+)#', function($match) {
        return pow($match[0], 2);
    }, $str
);
echo $res; // 4 9 16 25 36<?php
$array = [10, 20, 30, 40, 50];
$arrayIterator = new ArrayIterator($array);
foreach ($arrayIterator as $key => $value) {
    // Преобразование числового ключа в строку и добавление префикса
    $newKey = 'key_' . $key;
    
    // Удаление старого ключа
    $arrayIterator->offsetUnset($key);
    
    // Установка нового ключа с тем же значением
    $arrayIterator->offsetSet($newKey, $value);
}
// Преобразование итератора обратно в массив
$newArray = iterator_to_array($arrayIterator);
// Вывод нового массива
print_r($newArray);
?><?php
function getNestedValue($array, $path) {
    foreach ($path as $key) {
        if (!isset($array[$key])) {
            return null;
        }
        $array = $array[$key];
    }
    return $array;
}
$ar = array(
  "z" => array(
    "x" => array(
      "c" => array(
        "v" => array(
          "a" => 123,
          "b" => 321
        )
      )
    )
  )
);
$path = array("z", "x", "c");
$result = getNestedValue($ar, $path);
echo $result !== null ? "Значение: " . print_r($result, true) : "Элемент не найден";
?>SELECT
    ch.id_element,
    ch.`table`,
    ch.param,
    GROUP_CONCAT(cu.name) AS value_new
FROM
    c_history ch
LEFT JOIN
    c_object co ON co.id = ch.id_element
LEFT JOIN
    c_user cu ON FIND_IN_SET(cu.id, ch.value_old)
WHERE
    ch.`table` = 'c_object'
    AND ch.param = 'ids_user_merge'
GROUP BY
    ch.id_element, ch.`table`, ch.param;$basketItems = $test->getCollection()->toArray();
foreach ($basketItems as $item) {
    $productId = $item->getField('PRODUCT_ID');
    echo $productId;
}<?php
$folder = "Название папки на кириллице";
$encodedFolder = mb_convert_encoding($folder, "UTF7-IMAP", "UTF-8");
$imapStream = imap_open("{imap.example.com}" . $encodedFolder, $login, $password);
if ($imapStream === false) {
    echo "Ошибка: " . imap_last_error();
    exit;
}$encodedFolder = imap_utf7_encode($folder);      <?php
use Exception;
use Imagick;
abstract class NoBrightPixelsChecker
{
    protected string $imagePath;
    protected string $thresholdColor;
    protected Imagick $imagick;
    public function __construct(string $imagePath, string $thresholdColor = '#eeeeee')
    {
        $this->imagePath = $imagePath;
        $this->thresholdColor = $thresholdColor;
        $this->loadImage();
    }
    private function loadImage(): void
    {
        try {
            $this->imagick = new Imagick($this->imagePath);
        } catch (Exception $e) {
            throw new Exception('Failed to load image: ' . $e->getMessage());
        }
    }
    abstract public function checkImage(): bool;
}
class ThresholdMaskNoBrightPixelsChecker extends NoBrightPixelsChecker
{
    public function checkImage(): bool
    {
        list($rThreshold, $gThreshold, $bThreshold) = sscanf($this->thresholdColor, "#%02x%02x%02x");
        $imageClone = clone $this->imagick;
        $thresholdColor = new ImagickPixel("rgb($rThreshold, $gThreshold, $bThreshold)");
        $imageClone->thresholdImage($thresholdColor);
        $histogram = $imageClone->getImageHistogram();
        $whitePixelCount = 0;
        foreach ($histogram as $pixel) {
            $color = $pixel->getColor();
            if ($color['r'] == 255 && $color['g'] == 255 && $color['b'] == 255) {
                $whitePixelCount += $pixel->getColorCount();
            }
        }
        return $whitePixelCount === 0;
    }
}
// Пример использования
try {
    $checker = new ThresholdMaskNoBrightPixelsChecker('path/to/your/image.jpg');
    $result = $checker->checkImage();
    echo $result ? 'No bright pixels found' : 'Bright pixels found';
} catch (Exception $e) {
    echo 'Error: ' . $e->getMessage();
}
?>use libphonenumber\PhoneNumberUtil;
use libphonenumber\NumberParseException;
public function validatePhone($phone, $country): bool
{
    $phoneUtil = PhoneNumberUtil::getInstance();
    try {
        $phoneNumber = $phoneUtil->parse($phone, strtoupper($country));
        return $phoneUtil->isValidNumber($phoneNumber);
    } catch (NumberParseException $e) {
        return false;
    }
}import { parsePhoneNumberFromString } from 'libphonenumber-js';
$("#phoneinput").on('countrychange', function () {
    const country = window.iti.getSelectedCountryData().iso2.toUpperCase();
    const phone = $("#phoneinput").val();
    const phoneNumber = parsePhoneNumberFromString(phone, country);
    if (phoneNumber && phoneNumber.isValid()) {
        // Номер телефона валиден
    } else {
        // Номер телефона не валиден
    }
});$folder = addslashes("\\assets\\img\\product\\");$stmt = $mysql->prepare("INSERT INTO `catalog`(`Name_Product`, `Operator`, `Internet`, `Minuts`, `Sms`, `Price_tarif`, `Price_sim`, `image`) VALUES (?, ?, ?, ?, ?, ?, ?, ?)");
$stmt->bind_param("ssssssss", $Name_Product, $Operator, $Internet, $Minuts, $Sms, $Price_tarif, $Price_sim, $photoname);
$stmt->execute();$output = null;
$retval = null;
exec("sudo ipset add bad_ips $bad_ip", $output, $retval);
if ($retval == 0) {
    echo "IP успешно добавлен";
} else {
    echo "Ошибка при добавлении IP";
}