是否有用于电话号码验证的正则表达式？

Question

I'm setting up a new website, and want to validate user input phone number. What Regex expression do I need to use to get the format 04xx xxx xxx? There needs to be a space between the fifth and ninth character.

I have tried using this expression: ^[+]*[(]{0,1}[0-9]{1,4}[)]{0,1}[-\\s\\./0-9]*$ .

    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Threading.Tasks;
    using System.ComponentModel.DataAnnotations;

    namespace InspiringMagazines.Models
    {
        public class Customer
        {
                public int customerID { get; set; }
                [Display(Name = "GivenName")]
                [MinLength(2), StringLength(20), Required(ErrorMessage =                                                         
    @"The Given Name is required.")]
                [RegularExpression(@"[0-9][a-z'-]{3,20}")]
                public string firstName { get; set; }
                [Display(Name = "FamilyName")]
                [MinLength(2), StringLength(20), Required(ErrorMessage =         
    @"The Family Name is required.")]
                [RegularExpression(@"[0-9][a-z'-]{3,20}")]
                public string lastName { get; set; }
                [Display(Name = "Date of Birth")]
                public string dateOfBirth { get; set; }
                public string emailAddress { get; set; }
                [MinLength(12), StringLength(12), Required(ErrorMessage =         
    @"The Phone Number is required.")]

                public string mobileNumber { get; set; }
                public string postalCode { get; set; }
        }
    }

Expected result is to have phone numbers not in the format of 04xx xxx xxx to show an error message. The actual result right now is all the numbers are being accepted.

Answer 1

The simplest regex in terms of comprehension would be:

^04\d\d \d\d\d \d\d\d$

But beware, this would probably let them type in Unicode numbers outside the ascii range too

To be honest, excessive validation is more irritating to users than it is helpful to you, especially when your error messages are so poor. Having some complicated requirement for input and then only telling them "the given name is required" is bad. What if their name really is "Q"? You don't say "given name must be at least two characters" (better error message) but then my question in this is "why must a name be at least two characters?" What do you care if a person puts one character in as their name?

Likewise for phone numbers , let them type in whatever they like, any old how. Strip all the crap they typed in when you validate and check they entered 10 digits starting with 04. The error message should say "phone number should start with 04 and have 10 digits in total". Prepopulate the box with 04 to help them out, and run this on what they give you:

Regex.Replace(theirInput, "[^0-9]", "");

It strips out all the hyphens, brackets, spaces etc. Check the length of the result. The message here is: "don't require your user to type spaces in because the spaces really don't matter. You can put them in yourself in code, after you strip the user input of (0400) 223-456 down to just numbers 0400223456 , simply using string substring

"Be tolerant of what you accept and strict of what you send" is the mantra for writing servers that talk HTTP, but it's a good thing to apply to any user input; Always aim to take as much varied junk input off the user and clean it up to meet your standards rather than forcing the user to meet it, and if you are forcing the user, definitely tell them exactly where they're going wrong. Aim for validation that feeds back instantly- don't have them submit the whole form then reject it and sent them back to one that is missing the values for its complicated double passwords fields and have them redo the captcha, or worse blank out all their input that was invalid

Answer 2

I tried with this regex

^(04\d{2}\s\d{3}\s\d{3})$

Tested on regexr

Answer 3

For Nigerian phone numbers the following regex pattern works [0]([7-9][0]|[8][0-1])[0-9]{8} . Just paste it in your Regex match

Answer 4

regex for nigerian phone number

without spacing

 /^234[0-9]{10}$/

with spacing

/^234\s[0-9]{10}$/