regex expression for any letters, space, Apostrophe and blank input - regex

this is the current expression i'm using, but when i input a value it only accepts 1 letter
when i input more than 1 i get an invalid input.
"regex":"/^(?:[a-zA-Z\ \']{30}|)$/",
what type of expression might be suitable for the input that i'm looking for?
ex:
John Franklin
or
(blank input)

The following should work for you:
/^([a-zA-Z ']*)$/
I've tested it and it appears to fit your needs.
For clarity, * means 'match 0 or any number of characters', which from my testing, satisfies your 'blank' requirement.

Letters, space, apostrophe, or blank:
/^[A-Za-z ']*$/
If you are capping it at 30 characters, then replace * with {0,30}. In some regex flavours you can omit the 0 and use {,30}.

x{30} means "exactly 30 instances of x". It sounds like you actually want up to 30 characters:
/^[a-zA-Z\ \']{0,30}$/
(using the {m,n} notation, meaning "between m and n instances").

Related

Regex for name with non-latin characters in python [duplicate]

For website validation purposes, I need first name and last name validation.
For the first name, it should only contain letters, can be several words with spaces, and has a minimum of three characters, but a maximum at top 30 characters. An empty string shouldn't be validated (e.g. Jason, jason, jason smith, jason smith, JASON, Jason smith, jason Smith, and jason SMITH).
For the last name, it should be a single word, only letters, with at least three characters, but at most 30 characters. Empty strings shouldn't be validated (e.g. lazslo, Lazslo, and LAZSLO).
Don't forget about names like:
Mathias d'Arras
Martin Luther King, Jr.
Hector Sausage-Hausen
This should do the trick for most things:
/^[a-z ,.'-]+$/i
OR Support international names with super sweet unicode:
/^[a-zA-ZàáâäãåąčćęèéêëėįìíîïłńòóôöõøùúûüųūÿýżźñçčšžÀÁÂÄÃÅĄĆČĖĘÈÉÊËÌÍÎÏĮŁŃÒÓÔÖÕØÙÚÛÜŲŪŸÝŻŹÑßÇŒÆČŠŽ∂ð ,.'-]+$/u
You make false assumptions on the format of first and last name. It is probably better not to validate the name at all, apart from checking that it is empty.
After going through all of these answers I found a way to build a tiny regex that supports most languages and only allows for word characters. It even supports some special characters like hyphens, spaces and apostrophes. I've tested in python and it supports the characters below:
^[\w'\-,.][^0-9_!¡?÷?¿/\\+=##$%ˆ&*(){}|~<>;:[\]]{2,}$
Characters supported:
abcdefghijklmnopqrstwxyz
ABCDEFGHIJKLMNOPQRSTUVWXYZ
áéíóúäëïöüÄ'
陳大文
łŁőŐűŰZàáâäãåąčćęèéêëėįìíîïłńòóôöõøùúûüųū
ÿýżźñçčšžÀÁÂÄÃÅĄĆČĖĘÈÉÊËÌÍÎÏĮŁ
ŃÒÓÔÖÕØÙÚÛÜŲŪŸÝŻŹÑßÇŒÆČŠŽ.-
ñÑâê都道府県Федерации
আবাসযোগ্য জমির걸쳐 있는
I have created a custom regex to deal with names:
I have tried these types of names and found working perfect
John Smith
John D'Largy
John Doe-Smith
John Doe Smith
Hector Sausage-Hausen
Mathias d'Arras
Martin Luther King
Ai Wong
Chao Chang
Alzbeta Bara
My RegEx looks like this:
^([a-zA-Z]{2,}\s[a-zA-Z]{1,}'?-?[a-zA-Z]{2,}\s?([a-zA-Z]{1,})?)
MVC4 Model:
[RegularExpression("^([a-zA-Z]{2,}\\s[a-zA-Z]{1,}'?-?[a-zA-Z]{2,}\\s?([a-zA-Z]{1,})?)", ErrorMessage = "Valid Charactors include (A-Z) (a-z) (' space -)") ]
Please note the double \\ for escape characters
For those of you that are new to RegEx I thought I'd include a explanation.
^ // start of line
[a-zA-Z]{2,} // will except a name with at least two characters
\s // will look for white space between name and surname
[a-zA-Z]{1,} // needs at least 1 Character
\'?-? // possibility of **'** or **-** for double barreled and hyphenated surnames
[a-zA-Z]{2,} // will except a name with at least two characters
\s? // possibility of another whitespace
([a-zA-Z]{1,})? // possibility of a second surname
I have searched and searched and played and played with it and although it is not perfect it may help others making the attempt to validate first and last names that have been provided as one variable.
In my case, that variable is $name.
I used the following code for my PHP:
if (preg_match('/\b([A-Z]{1}[a-z]{1,30}[- ]{0,1}|[A-Z]{1}[- \']{1}[A-Z]{0,1}
[a-z]{1,30}[- ]{0,1}|[a-z]{1,2}[ -\']{1}[A-Z]{1}[a-z]{1,30}){2,5}/', $name)
# there is no space line break between in the above "if statement", any that
# you notice or perceive are only there for formatting purposes.
#
# pass - successful match - do something
} else {
# fail - unsuccessful match - do something
I am learning RegEx myself but I do have the explanation for the code as provided by RegEx buddy.
Here it is:
Assert position at a word boundary «\b»
Match the regular expression below and capture its match into backreference number 1
«([A-Z]{1}[a-z]{1,30}[- ]{0,1}|[A-Z]{1}[- \']{1}[A-Z]{0,1}[a-z]{1,30}[- ]{0,1}|[a-z]{1,2}[ -\']{1}[A-Z]{1}[a-z]{1,30}){2,5}»
Between 2 and 5 times, as many times as possible, giving back as needed (greedy) «{2,5}»
* I NEED SOME HELP HERE WITH UNDERSTANDING THE RAMIFICATIONS OF THIS NOTE *
Note: I repeated the capturing group itself. The group will capture only the last iteration. Put a capturing group around the repeated group to capture all iterations. «{2,5}»
Match either the regular expression below (attempting the next alternative only if this one fails) «[A-Z]{1}[a-z]{1,30}[- ]{0,1}»
Match a single character in the range between “A” and “Z” «[A-Z]{1}»
Exactly 1 times «{1}»
Match a single character in the range between “a” and “z” «[a-z]{1,30}»
Between one and 30 times, as many times as possible, giving back as needed (greedy) «{1,30}»
Match a single character present in the list “- ” «[- ]{0,1}»
Between zero and one times, as many times as possible, giving back as needed (greedy) «{0,1}»
Or match regular expression number 2 below (attempting the next alternative only if this one fails) «[A-Z]{1}[- \']{1}[A-Z]{0,1}[a-z]{1,30}[- ]{0,1}»
Match a single character in the range between “A” and “Z” «[A-Z]{1}»
Exactly 1 times «{1}»
Match a single character present in the list below «[- \']{1}»
Exactly 1 times «{1}»
One of the characters “- ” «- » A ' character «\'»
Match a single character in the range between “A” and “Z” «[A-Z]{0,1}»
Between zero and one times, as many times as possible, giving back as needed (greedy) «{0,1}»
Match a single character in the range between “a” and “z” «[a-z]{1,30}»
Between one and 30 times, as many times as possible, giving back as needed (greedy) «{1,30}»
Match a single character present in the list “- ” «[- ]{0,1}»
Between zero and one times, as many times as possible, giving back as needed (greedy) «{0,1}»
Or match regular expression number 3 below (the entire group fails if this one fails to match) «[a-z]{1,2}[ -\']{1}[A-Z]{1}[a-z]{1,30}»
Match a single character in the range between “a” and “z” «[a-z]{1,2}»
Between one and 2 times, as many times as possible, giving back as needed (greedy) «{1,2}»
Match a single character in the range between “ ” and “'” «[ -\']{1}»
Exactly 1 times «{1}»
Match a single character in the range between “A” and “Z” «[A-Z]{1}»
Exactly 1 times «{1}»
Match a single character in the range between “a” and “z” «[a-z]{1,30}»
Between one and 30 times, as many times as possible, giving back as needed (greedy) «{1,30}»
I know this validation totally assumes that every person filling out the form has a western name and that may eliminates the vast majority of folks in the world. However, I feel like this is a step in the proper direction. Perhaps this regular expression is too basic for the gurus to address simplistically or maybe there is some other reason that I was unable to find the above code in my searches. I spent way too long trying to figure this bit out, you will probably notice just how foggy my mind is on all this if you look at my test names below.
I tested the code on the following names and the results are in parentheses to the right of each name.
STEVE SMITH (fail)
Stev3 Smith (fail)
STeve Smith (fail)
Steve SMith (fail)
Steve Sm1th (passed on the Steve Sm)
d'Are to Beaware (passed on the Are to Beaware)
Jo Blow (passed)
Hyoung Kyoung Wu (passed)
Mike O'Neal (passed)
Steve Johnson-Smith (passed)
Jozef-Schmozev Hiemdel (passed)
O Henry Smith (passed)
Mathais d'Arras (passed)
Martin Luther King Jr (passed)
Downtown-James Brown (passed)
Darren McCarty (passed)
George De FunkMaster (passed)
Kurtis B-Ball Basketball (passed)
Ahmad el Jeffe (passed)
If you have basic names, there must be more than one up to five for the above code to work, that are similar to those that I used during testing, this code might be for you.
If you have any improvements, please let me know. I am just in the early stages (first few months of figuring out RegEx.
Thanks and good luck,
Steve
I've tried almost everything on this page, then I decided to modify the most voted answer which ended up working best. Simply matches all languages and includes .,-' characters.
Here it is:
/^[\p{L} ,.'-]+$/u
First name would be
"([a-zA-Z]{3,30}\s*)+"
If you need the whole first name part to be shorter than 30 letters, you need to check that seperately, I think. The expression ".{3,30}" should do that.
Your last name requirements would translate into
"[a-zA-Z]{3,30}"
but you should check these. There are plenty of last names containing spaces.
As maček said:
Don't forget about names like:
Mathias d'Arras
Martin Luther King, Jr.
Hector Sausage-Hausen
and to remove cases like:
..Mathias
Martin king, Jr.-
This will cover more cases:
^([a-z]+[,.]?[ ]?|[a-z]+['-]?)+$
This regex work for me (was using in Angular 8) :
([a-zA-Z',.-]+( [a-zA-Z',.-]+)*){2,30}
It will be invalid if there is:-
Any whitespace start or end of the name
Got symbols e.g. #
Less than 2 or more than 30
Example invalid First Name (whitespace)
Example valid First Name :
I'm working on the app that validates International Passports (ICAO). We support only english characters. While most foreign national characters can be represented by a character in the Latin alphabet e.g. è by e, there are several national characters that require an extra letter to represent them such as the German umlaut which requires an ‘e’ to be added to the letter e.g. ä by ae.
This is the JavaScript Regex for the first and last names we use:
/^[a-zA-Z '.-]*$/
The max number of characters on the international passport is up to 31.
We use maxlength="31" to better word error messages instead of including it in the regex.
Here is a snippet from our code in AngularJS 1.6 with form and error handling:
class PassportController {
constructor() {
this.details = {};
// English letters, spaces and the following symbols ' - . are allowed
// Max length determined by ng-maxlength for better error messaging
this.nameRegex = /^[a-zA-Z '.-]*$/;
}
}
angular.module('akyc', ['ngMessages'])
.controller('PassportController', PassportController);
.has-error p[ng-message] {
color: #bc111e;
}
.tip {
color: #535f67;
}
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.6.6/angular.min.js"></script>
<script src="https://code.angularjs.org/1.6.6/angular-messages.min.js"></script>
<main ng-app="akyc" ng-controller="PassportController as $ctrl">
<form name="$ctrl.form">
<div name="lastName" ng-class="{ 'has-error': $ctrl.form.lastName.$invalid} ">
<label for="pp-last-name">Surname</label>
<div class="tip">Exactly as it appears on your passport</div>
<div ng-messages="$ctrl.form.lastName.$error" ng-if="$ctrl.form.$submitted" id="last-name-error">
<p ng-message="required">Please enter your last name</p>
<p ng-message="maxlength">This field can be at most 31 characters long</p>
<p ng-message="pattern">Only English letters, spaces and the following symbols ' - . are allowed</p>
</div>
<input type="text" id="pp-last-name" ng-model="$ctrl.details.lastName" name="lastName"
class="form-control" required ng-pattern="$ctrl.nameRegex" ng-maxlength="31" aria-describedby="last-name-error" />
</div>
<button type="submit" class="btn btn-primary">Test</button>
</form>
</main>
Read almost all highly voted posts (only some are good). After understanding the problem in detail & doing research, here are the tight regexes:
1). ^[A-Z][a-z]*(([,.] |[ '-])[A-Za-z][a-z]*)*(\.?)$
name Z is allowed contrary to the assumption made by some in the thread.
No leading or trailing spaces are allowed, empty string is NOT allowed, string containing only spaces is NOT allowed
Supports English alphabets only
Supports hyphens (Some-Foobarbaz-name, Some foobarbaz-Name), apostrophes (David D'Costa, David D'costa, David D'costa R'Costa p'costa), periods (Dr. L. John, Robert Downey Jr., Md. K. P. Asif) and commas (Martin Luther, Jr.).
First alphabet of only the first word of a name MUST be capital.
NOT Allowed: John sTeWaRT, JOHN STEWART, Md. KP Asif, John Stewart PhD
Allowed: John Stewart, John stewart, Md. K P Asif
you can easily modify this condition.
If you also want to allow names like Queen Elizabeth 2 or Henry IV:
2). ^[A-Z][a-z]*(([,.] |[ '-])[A-Za-z][a-z]*)*([.]?| (-----)| [1-9][0-9]*)$
replace ----- with roman numeral's regex (which itself is long) OR you can use this alternative regex which is based on KISS philosophy [IVXLCDM]+ (here I, V, X, ... in ANY random order will satisfy the regex).
I personally suggest to use this regex:
3). ^[A-Z][a-z]*(([,.] |[ '-])[A-Za-z][a-z]*)*(\.?)( [IVXLCDM]+)?$
Feel free to try this regex HERE & make any modifications of your choice.
I have provided with tight regex which covers every possible name I found on my research with no bug. Modify these regexes to relax some of the unwanted constraints.
[UPDATE - March, 2022]
Here are 4 more regexes:
^[A-Za-z]+(([,.] |[ '-])[A-Za-z]+)*([.,'-]?)$
^((([,.'-]| )(?<!( {2}|[,.'-]{2})))*[A-Za-z]+)+[,.'-]?$
^( ([A-Za-z,.'-]+|$))+|([A-Za-z,.'-]+( |$))+$
^(([ ,.'-](?<!( {2}|[,.'-]{2})))*[A-Za-z])+[ ,.'-]?$
It's been a while since I looked back at these 4 regexes so I forgot their specifications. These 4 regexes are not tight, unlike the previous ones but do the job very well. These regexes distinguish 3 parts of a name: English alphabet, space and special character. Which one you need out of these 4 depends on your answer (Yes/No) to these questions:
have at least 1 alphabet?
can start with a space or a special character?
can end with a space or a special character?
are 2 consecutive spaces allowed?
are 2 consecutive special characters allowed?
Note: name validation should ONLY serve as a warning NOT a necessity a name should fulfill because there is no fixed naming pattern, if there is one it can change overnight and thus, any tight regex you come across will become obsolete somewhere in future.
There is one issue with the top voted answer here which recommends this regex:
/^[a-z ,.'-]+$/i
It takes spaces only as a valid name!
The best solution in my opinion is to add a negative look forward to the beginning:
^(?!\s)([a-z ,.'-]+)$/i
I use:
/^(?:[\u00c0-\u01ffa-zA-Z'-]){2,}(?:\s[\u00c0-\u01ffa-zA-Z'-]{2,})+$/i
And test for maxlength using some other means
I didn't find any answer helpful for me simply because users can pick a non-english name and simple regex are not helpful. In fact it's actually very hard to find the right expression that works for all languages.
Instead, I picked a different approach and negated all characters that should not be in the name for the valid match. Below pattern negates numerical, special characters, control characters and '\', '/'
Final regex
without punctuations: ["] ['] [,] [.], etc. :
^([^\p{N}\p{S}\p{C}\p{P}]{2,20})$
with punctuations:
^([^\p{N}\p{S}\p{C}\\\/]{2,20})$
With this, all these names are valid:
alex junior
沐宸
Nick
Sarah's Jane ---> with punctuation support
ביממה
حقیقت
Виктория
And following names become invalid:
🤣 Maria
k
١١١١١
123John
This means all names that don't have numerical characters, emojis, \ and are between 2-20 characters are allowed. You can edit the above regex if you want to add more characters to exclusion list.
To get more information about available patterns to include / exclude checkout this:
https://www.regular-expressions.info/unicode.html#prop
^\p{L}{2,}$
^ asserts position at start of a line.
\p{L} matches any kind of letter from any language
{2,} Quantifier — Matches between 2 and unlimited times, as many times as possible, giving back as needed (greedy)
$ asserts position at the end of a line
So it should be a name in any language containing at least 2 letters(or symbols) without numbers or other characters.
If you are searching a simplest way, just check almost 2 words.
/^[^\s]+( [^\s]+)+$/
Valid names
John Doe
pedro alberto ch
Ar. Gen
Mathias d'Arras
Martin Luther King, Jr.
No valid names
John
陳大文
For simplicities sake, you can use:
(.*)\s(.*)
The thing I like about this is that the last name is always after the first name, so if you're going to enter this matched groups into a database, and the name is John M. Smith, the 1st group will be
John M., and the 2nd group will be Smith.
So, with customer we create this crazy regex:
(^$)|(^([^\-!#\$%&\(\)\*,\./:;\?#\[\\\]_\{\|\}¨ˇ“”€\+<=>§°\d\s¤®™©]| )+$)
For first and last names theres are really only 2 things you should be looking for:
Length
Content
Here is my regular expression:
var regex = /^[A-Za-z-,]{3,20}?=.*\d)/
1. Length
Here the {3,20} constrains the length of the string to be between 3 and 20 characters.
2. Content
The information between the square brackets [A-Za-z] allows uppercase and lowercase characters. All subsequent symbols (-,.) are also allowed.
The following expression will work on any language supported by UTF-16 and will ensure that there's a minimum of two components to the name (i.e. first + last), but will also allow any number of middle names.
/^(\S+ )+\S+$/u
At the time of this writing it seems none of the other answers meet all of that criteria. Even ^\p{L}{2,}$, which is the closest, falls short because it will also match "invisible" characters, such as U+FEFF (Zero Width No-Break Space).
Try these solutions, for maximum compatibility, as I have already posted here:
JavaScript:
var nm_re = /^(?:((([^0-9_!¡?÷?¿/\\+=##$%ˆ&*(){}|~<>;:[\]'’,\-.\s])){1,}(['’,\-\.]){0,1}){2,}(([^0-9_!¡?÷?¿/\\+=##$%ˆ&*(){}|~<>;:[\]'’,\-. ]))*(([ ]+){0,1}(((([^0-9_!¡?÷?¿/\\+=##$%ˆ&*(){}|~<>;:[\]'’,\-\.\s])){1,})(['’\-,\.]){0,1}){2,}((([^0-9_!¡?÷?¿/\\+=##$%ˆ&*(){}|~<>;:[\]'’,\-\.\s])){2,})?)*)$/;
HTML5:
<input type="text" name="full_name" id="full_name" pattern="^(?:((([^0-9_!¡?÷?¿/\\+=##$%ˆ&*(){}|~<>;:[\]'’,\-.\s])){1,}(['’,\-\.]){0,1}){2,}(([^0-9_!¡?÷?¿/\\+=##$%ˆ&*(){}|~<>;:[\]'’,\-. ]))*(([ ]+){0,1}(((([^0-9_!¡?÷?¿/\\+=##$%ˆ&*(){}|~<>;:[\]'’,\-\.\s])){1,})(['’\-,\.]){0,1}){2,}((([^0-9_!¡?÷?¿/\\+=##$%ˆ&*(){}|~<>;:[\]'’,\-\.\s])){2,})?)*)$" required>
This is what I use.
This regex accepts only names with minimum characters, from A-Z a-z ,space and -.
Names example:
Ionut Ionete, Ionut-Ionete Cantemir, Ionete Ionut-Cantemirm Ionut-Cantemir Ionete-Second
The limit of name's character is 3. If you want to change this, modify {3,} to {6,}
([a-zA-Z\-]+){3,}\s+([a-zA-Z\-]+){3,}
This seems to do the job for me:
[\S]{2,} [\S]{2,}( [\S]{2,})*
I usually write:
return /^[a-zA-Z\-\s\.\'\`\u00E0-\u00FC]+$/.test(firstName);
Fullname with only one whitespace:
^[a-zA-Z'\-\pL]+(?:(?! {2})[a-zA-Z'\-\pL ])*[a-zA-Z'\-\pL]+$
A simple function using preg_match in php
<?php
function name_validation($name) {
if (!preg_match("/^[a-zA-Z ]*$/", $name) === false) {
echo "$name is a valid name";
} else {
echo "$name is not a valid name";
}
}
//Test
name_validation('89name');
?>
If you want the whole first name to be between 3 and 30 characters with no restrictions on individual words, try this :
[a-zA-Z ]{3,30}
Beware that it excludes all foreign letters as é,è,à,ï.
If you want the limit of 3 to 30 characters to apply to each individual word, Jens regexp will do the job.
var name = document.getElementById('login_name').value;
if ( name.length < 4 && name.length > 30 )
{
alert ( 'Name length is mismatch ' ) ;
}
var pattern = new RegExp("^[a-z\.0-9 ]+$");
var return_value = var pattern.exec(name);
if ( return_value == null )
{
alert ( "Please give valid Name");
return false;
}

best approach for my pattern match

So, I've built a regex which follows this:
4!a2!a2!c[3!c]
which is translated to
4 alpha character followed by
2 alpha characters followed by
2 characters followed by
3 optional character
this is a standard format for SWIFT BIC code HSBCGB2LXXX
my regex to pull this out of string is:
(?<=:32[^:]:)(([a-zA-Z]{4}[a-zA-Z]{2})[0-9][a-zA-Z]{1}[X]{3})
Now this is targeting a specific tag (32) and works, however, I'm not sure if it's the cleanest, plus if there are any characters before H then it fails.
the string being matched against is:
:32B:HsBfGB4LXXXHELLO
the following returns HSBCGB4LXXX, but this:
:32B:2HsBfGB4LXXXHELLO
returns nothing.
EDIT
For clarity. I have a string which contains multiple lines all starting with :2xnumber:optional letter (eg, :58A:) i want to specify a line to start matching in and return a BIC from anywhere in the line.
EDIT
Some more example data to help:
:20:ABCDERF Z
:23B:CRED
:32A:140310AUD2120,
:33B:AUD2120,
:50K:/111222333
Mr Bank of Dad
Dads house
England
:52D:/DBEL02010987654321
address 1
address 2
:53B:/HSBCGB2LXXX
:57A://AU124040
AREFERENCE
:59:/44556677
A line which HSBCGB2LXXX contains a BIC
:70:Another line of data
:71A:Even more
Ok, so I need to pass in as a variable the tag 53 or 59 and return the BIC HSBCGB2LXXX only!
Your regex can be simplified, and corrected to allow a character before the H, to:
:32[^:]:.?([a-zA-Z]{6}\d[a-zA-Z]XXX)
The changes made were:
Lost the look behind - just make it part of the match
Inserting .? meaning "optional character"
([a-zA-Z]{4}[a-zA-Z]{2}) ==> [a-zA-Z]{6} (4+2=6)
[0-9] ==> \d (\d means "any digit")
[X]{3} ==> XXX (just easier to read and less characters)
Group 1 of the match contains your target
I'm not quite sure if I understand your question completely, as your regular expression does not completely match what you have described above it. For example, you mentioned 3 optional characters, but in the regexp you use 3 mandatory X-es.
However, the actual regular expression can be further cleaned:
instead of [a-zA-Z]{4}[a-zA-Z]{2}, you can simply use [a-zA-Z]{6}, and the grouping parentheses around this might be unnecessary;
the {1} can be left out without any change in the result;
the X does not need surrounding brackets.
All in all
(?<=:32[^:]:)([a-zA-Z]{6}[0-9][a-zA-Z]X{3})
is shorter and matches in the very same cases.
If you give a better description of the domain, probably further improvements are also possible.

Regex to check for at least 3 characters?

I have this regex to allow for only alphanumeric characters.
How can I check that the string at least contains 3 alphabet characters as well.
My current regex,
if(!/^[a-zA-Z0-9]+$/.test(val))
I want to enforce the string to make sure there is at least 3 consecutive alphabet characters as well so;
111 // false
aaa1 // true
11a // false
bbc // true
1a1aa // false
+ means "1 or more occurrences."
{3} means "3 occurrences."
{3,} means "3 or more occurrences."
+ can also be written as {1,}.
* can also be written as {0,}.
To enforce three alphabet characters anywhere,
/(.*[a-z]){3}/i
should be sufficient.
Edit. Ah, you'ved edited your question to say the three alphabet characters must be consecutive. I also see that you may want to enforce that all characters should match one of your "accepted" characters. Then, a lookahead may be the cleanest solution:
/^(?.*[a-z]{3})[a-z0-9]+$/i
Note that I am using the case-insensitive modifier /i in order to avoid having to write a-zA-Z.
Alternative. You can read more about lookaround assertions here. But it may be a little bit over your head at this stage. Here's an alternative that you may find easier to break down in terms of what you already know:
/^([a-z0-9]*[a-z]){3}[a-z0-9]*$/i
This should do the work:
^([0-9]*[a-zA-Z]){3,}[0-9]*$
It checks for at least 3 "Zero-or-more numerics + 1 Alpha" sequences + Zero-or-more numerics.
You want to match zero or more digits then 3 consecutive letters then any other number of digits?
/\d*(?:[a-zA-Z]){3,}\d*/
This is vanilla JS you guys can use. My problem is solved using this.
const str = "abcdggfhf";
const pattern = "fhf";
if(pattern.length>2) {
console.log(str.search(pattern));
}

Regular Expression Validation for a Phone no that will accept nos,dashes and +

I just need a Regular Expression that will validate a phone no entered in the textbox. That textbox can allow only numbers,dashes(-) and plus(+) and should be maximum of 15 characters and minimum of 11 characters.
(+) can(Optional) only come at starting of phone no.
Please answer.
Your question is answered by this:
\+?[\d-]{1,13}
\+? means "zero of one '+' character"
[\d-]{1,13} means "from 1 to 13 digits or hyphen"
However, I think you should use something a little more prescriptive. Perhaps requiring there's at least say 8 digits and the hyphen can't be first or last:
^(?=(.*\d){8,13})\+?(?!-)[\d-]*(?<!-)$
Disregarding your 13 character constraint, you can use this regex:
^((\+[0-9]([0-9]{2}|[1-9])?-)?([1-9][0-9]{2}-)?[1-9][0-9]{2}-[0-9]{4})?$

Custom RegEx expression for validating different possibilities of phone number entries?

I'm looking for a custom RegEx expression (that works!) to will validate common phone number with area code entries (no country code) such as:
111-111-1111
(111) 111-1111
(111)111-1111
111 111 1111
111.111.1111
1111111111
And combinations of these / anything else I may have forgotton.
Also, is it possible to have the RegEx expression itself reformat the entry? So take the 1111111111 and put it in 111-111-1111 format. The regex will most likely be entered in a Joomla / some type of CMS module, so I can't really add code to it aside from the expression itself.
\(?(\d{3})\)?[ .-]?(\d{3})[ .-]?(\d{4})
will match all your examples; after a match, backreference 1 will contain the area code, backreference 2 and 3 will contain the phone number.
I hope you don't need to handle international phone numbers, too.
If the phone number is in a string by itself, you could also use
^\s*\(?(\d{3})\)?[ .-]?(\d{3})[ .-]?(\d{4})\s*$
allowing for leading/trailing whitespace and nothing else.
Why not just remove spaces, parenthesis, dashes, and periods, then check that it is a number of 10 digits?
Depending on the language in question, you might be better off using a replace-like statement to replace non-numeric characters: ()-/. with nothing, and then just check if what is left is a 10-digit number.