libphonenumber\PhoneNumberUtil::getRegionCodeForNumberFromRegionList PHP 메소드

    protected function getRegionCodeForNumberFromRegionList(PhoneNumber $number, array $regionCodes)
    {
        $nationalNumber = $this->getNationalSignificantNumber($number);
        foreach ($regionCodes as $regionCode) {
            // If leadingDigits is present, use this. Otherwise, do full validation.
            // Metadata cannot be null because the region codes come from the country calling code map.
            $metadata = $this->getMetadataForRegion($regionCode);
            if ($metadata->hasLeadingDigits()) {
                $nbMatches = preg_match('/' . $metadata->getLeadingDigits() . '/', $nationalNumber, $matches, PREG_OFFSET_CAPTURE);
                if ($nbMatches > 0 && $matches[0][1] === 0) {
                    return $regionCode;
                }
            } elseif ($this->getNumberTypeHelper($nationalNumber, $metadata) != PhoneNumberType::UNKNOWN) {
                return $regionCode;
            }
        }
        return null;
    }