Regex for Dutch telephone numbers - php

Question

I'm definitely not the worst when it comes down to regex, but this one has got me stumped.
In short, this is the code I currently have.
$aNumbers = array(
'612345678',
'546123465',
'131234567',
'[phone]'
);
foreach($aNumbers as $sNumber) {
$aMatches = array();
$sNumber = preg_replace('/(\(0\)|[^\d]+)/', '', $sNumber);
preg_match('/(\d{1,2})?(\d{3})(\d{3})(\d{3})$/', $sNumber, $aMatches);
var_dump($sNumber);
var_dump($aMatches);
}
Simply put, I want to match specific formats for telephone numbers to ensure a unified display.
[phone]
[phone]
Both stripped would be without + and (0).
Cut down in parts:
31 6 123 456 78
Country Net Number
31 13 123 456 78
Country Net Number
Now, in some cases the +31 (or +1, +222) are optional. The 6 and 13 are always included, but as a fun twist, the following format is also possible:
31 546 123 456
Country Net Number
Is this even possible with regex?

Answer 1

I've answered a few of these types of questions, and my strategy is to identify certain portions of formatting or number relationships that convey meaning, and get rid of the rest.
One of my examples that parses non-NANP number formatting uses a list of valid area codes in the parsing expression, and identifies country code when present. It extracts the country code, area code, and then the rest of the number.
or your country, I am assuming the list of area/net/region codes in HansM's answer is either correct or easily replaceable, so I'll guess that this modification of a regex might be useful:
^[ -]*(\+31)?[ -]*[(0)]*[ -]*(7|43|32|45|33|49|39|31|47|34|46|41|90|44|351|353|358)[ -]*((?:\d[ -]*)+)
It will first match the country code, if it is present, and store it in back-reference 1, then ignore a single zero. It will then match one of the area/net/region codes and store it in back-reference 2. It will then get any number of digits (one or more), mixed with dashes (-) and/or spaces () and store those into back-reference 3
After this, you could parse the third numbering group for validity or further reformatting
I'm testing it on Regex 101, but I could use a list of acceptable and unacceptable input, and how it should be reformatted when acceptable...
[EDIT]
I've used this list of city codes for the Netherlands and modified the expression thusly:
^[ -]*(\+31)?[ -]*[(0)]*[ -]*([123457]0|23|24|26|35|45|71|73|570)[ -]*((?:\d[ -]*)+)
which performs the following parsing:
input (1) (2) (3)
--------------------- ------ ------ ---------------
0707123456 70 7123456
0267-123456 26 7-123456
0407-12 34 56 40 7-12 34 56
0570123456 570 123456
07312345 73 12345
[phone] [phone]
but I still don't know if that's helpful for you
[EDIT 2]
Wikipedia has what appears to be a more comprehensive list of codes
010, 0111, 0113, 0114, 0115, 0117, 0118, 013, 015, 0161, 0162, 0164, 0165, 0166, 0167, 0168, 0172, 0174, 0180, 0181, 0182, 0183, 0184, 0186, 0187, 020, 0222, 0223, 0224, 0226, 0227, 0228, 0229, 023, 024, 0251, 0252, 0255, 026, 0294, 0297, 0299, 030, 0313, 0314, 0315, 0316, 0317, 0318, 0320, 0321, 033, 0341, 0342, 0343, 0344, 0345, 0346, 0347, 0348, 035, 036, 038, 040, 0411, 0412, 0413, 0416, 0418, 043, 045, 046, 0475, 0478, 0481, 0485, 0486, 0487, 0488, 0492, 0493, 0495, 0497, 0499, 050, 0511, 0512, 0513, 0514, 0515, 0516, 0517, 0518, 0519, 0521, 0522, 0523, 0524, 0525, 0527, 0528, 0529, 053, 0541, 0543, 0544, 0545, 0546, 0547, 0548, 055, 0561, 0562, 0566, 0570, 0571, 0572, 0573, 0575, 0577, 0578, 058, 0591, 0592, 0593, 0594, 0595, 0596, 0597, 0598, 0599, 070, 071, 072, 073, 074, 075, 076, 077, 078, 079
which can be used in the code selection portion like this (if you'd prefer it to be more easily read and updated):
10|111|113|114|115|117|118|13|15|161|162|164|165|166|167|168|172|174|180|181|182|183|184|186|187|20|222|223|224|226|227|228|229|23|24|251|252|255|26|294|297|299|30|313|314|315|316|317|318|320|321|33|341|342|343|344|345|346|347|348|35|36|38|40|411|412|413|416|418|43|45|46|475|478|481|485|486|487|488|492|493|495|497|499|50|511|512|513|514|515|516|517|518|519|521|522|523|524|525|527|528|529|53|541|543|544|545|546|547|548|55|561|562|566|570|571|572|573|575|577|578|58|591|592|593|594|595|596|597|598|599|70|71|72|73|74|75|76|77|78|79
or like this (if you'd prefer a more efficient evaluation of the expression):
1([035]|1[134578]|6[124-8]|7[24]|8[0-467])|2([0346]|2[2346-9]|5[125]|9[479])|3([03568]|1[34-8]|2[01]|4[1-8])|4([0356]|1[12368]|7[58]|8[15-8]|9[23579])|5([0358]|[19][1-9]|2[1-5789]|4[13-8]|6[126]|7[0-3578])|7[0-9]

Answer 2

I have used the nuget package libphonenumber-csharp.
That has helped me to create a (Dutch) phone number validator, here is a code snippet, without other parts of my solution it will not compile but at least you can get an idea of how to handle this.
public override void Validate()
{
ValidationMessages = new Dictionary<string, string>();
ErrorMessage = string.Empty;
string phoneNumber;
string countryCode = _defaultCountryCode;
// If the phoneNumber is not required, it is allowed to be empty.
// So in that case isValid gets defaultvalue true
bool isValid = (!_isRequired);
if (!string.IsNullOrEmpty(_phoneNumber))
{
var phoneUtil = PhoneNumberUtil.GetInstance();
try
{
phoneNumber = PhoneNumbers.PhoneNumberUtil.Normalize(_phoneNumber);
countryCode = PhoneNumberUtil2.GetRegionCode(phoneNumber, _defaultCountryCode);
PhoneNumber oPhoneNumber = phoneUtil.Parse(phoneNumber, countryCode);
var t1 = oPhoneNumber.NationalNumber;
var t2 = oPhoneNumber.CountryCode;
var formattedNo = phoneUtil.Format(oPhoneNumber, PhoneNumberFormat.E164);
isValid = PhoneNumbers.PhoneNumberUtil.IsViablePhoneNumber(formattedNo);
}
catch (NumberParseException e)
{
var err = e.ToString();
isValid = false;
}
}
if ((isValid) && (!string.IsNullOrEmpty(_phoneNumber)))
{
Regex regexValidator = null;
string regex;
// Additional validations for Dutch phone numbers as LibPhoneNumber is to graceful as it comes to
// thinking if a number is valid.
switch (countryCode)
{
case "NL":
if (_phoneNumber.StartsWith("0800") || _phoneNumber.StartsWith("0900"))
{
// 0800/0900 numbers
regex = #"((0800|0900)(-| )?[0-9]{4}([0-9]{3})?$)";
regexValidator = new Regex(regex);
isValid = regexValidator.IsMatch(_phoneNumber);
}
else
{
string phoneNumberCheck = _phoneNumber.Replace("(", "").Replace(")", "").Replace("-", "").Replace(" ", "");
regex = #"^(0031|\+31|0)[1-9][0-9]{8}$";
regexValidator = new Regex(regex);
isValid = regexValidator.IsMatch(phoneNumberCheck);
}
break;
}
}
if (!isValid)
{
ErrorMessage = string.Format(TextProvider.Get(TextProviderConstants.ValMsg_IsInAnIncorrectFormat_0),
ColumnInfoProvider.GetLabel(_labelKey));
ValidationMessages.Add(_messageKey, ErrorMessage);
}
}
Also useful might be my class PhoneNumberUtil2 that builds upon the nuget package libphonenumber-csharp:
// Code start
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Text;
using PhoneNumbers;
namespace ProjectName.Logic.Miscellaneous
{
public class PhoneNumberUtil2
{
/// <summary>
/// Returns the alphanumeric country code for a normalized phonenumber. If a phonenumber does not contain
/// an international numeric country code, the default country code for the website is returned.
/// This works for 17 countries: NL, GB, FR, DE, BE, AU, SE, NO, IT, TK, RU, CH, DK, IR, PT, ES, FI
/// </summary>
/// <param name="normalizedPhoneNumber"></param>
/// <param name="defaultCountryCode"> </param>
/// <returns></returns>
public static string GetRegionCode(string normalizedPhoneNumber, string defaultCountryCode)
{
if (normalizedPhoneNumber.Length > 10)
{
var dict = new Dictionary<string, string>();
dict.Add("7", "RU");
dict.Add("43", "AT");
dict.Add("32", "BE");
dict.Add("45", "DK");
dict.Add("33", "FR");
dict.Add("49", "DE");
dict.Add("39", "IT");
dict.Add("31", "NL");
dict.Add("47", "NO");
dict.Add("34", "ES");
dict.Add("46", "SE");
dict.Add("41", "CH");
dict.Add("90", "TR");
dict.Add("44", "GB");
dict.Add("351", "PT");
dict.Add("353", "IE");
dict.Add("358", "FI");
// First check 3-digits International Calling Codes
if (dict.ContainsKey(normalizedPhoneNumber.Substring(0, 3)))
{
return dict[normalizedPhoneNumber.Substring(0, 3)];
}
// Then 2-digits International Calling Codes
if (dict.ContainsKey(normalizedPhoneNumber.Substring(0, 2)))
{
return dict[normalizedPhoneNumber.Substring(0, 2)];
}
// And finally 1-digit International Calling Codes
if (dict.ContainsKey(normalizedPhoneNumber.Substring(0, 1)))
{
return dict[normalizedPhoneNumber.Substring(0, 1)];
}
}
return defaultCountryCode;
}
}
}