In my requirement a Textbox should allow Alphabets,Numeric s, Special Characters,Special Symbols With at least one Alphabet.
I will try like this but i am not getting.
^\d*[a-zA-Z][a-zA-Z0-9#*,$._&% -!><^#]*$
You may want to have 2 regular expression validators; one for validating the allowed characters, and one for validating that at least on alphabet has been provided. You may be able to get at least one, but this way, you can have two separate validation messages to show the user explaining why the input is wrong.
Just match for special characters until you encounter a letter, then match for everything until the end of the string:
^[0-9#*,$._&% -!><^#]*[a-zA-Z0-9#*,$._&% -!><^#]*$
Use lookaheads :
/^(?=.*[a-zA-Z])[\w#*,$.&%!><^#-]*$/
Edit :
I assume the - is meant as the actual - character and not a range of space to !.
I removed the space character. You can of course add it if you want.
[ -!]
Effectively means :
[ -!] # Match a single character in the range between “ ” and “!”
And I have no idea what that range entails!
Related
I am trying to apply validation in Textbox control for limiting empty space in control. Following is the Regular Expression code I'm using:
Regularexpression validationexpression="^[^-\s][a-zA-Z0-9_\s-]+$" errortext="" />
Now my requirement is:
User should not enter empty space in begining. (Working fine)
Textbox limit is upto 10 numbers, user will able to enter as much as number he wants, no validation if he enter less than 10 numbers. (Working fine.)
validation should prompt if user enter the numbers like this "111
111 ", means show validation if there is empty space between
numbers. (Not working)
Currently I'm using following Regular Expression to achieve this thing, please let me know or update my regular expression so I can achieve this requirement.
Regularexpression validationexpression="^[^-\s][a-zA-Z0-9_\s-]+$" errortext="" />
^[a-zA-Z0-9_-]{1,10}$
Try this.See demo.
http://regex101.com/r/wQ1oW3/23
you can use a regex like
^[^\s][\d\w_-]{1,10}$
which will match as
http://regex101.com/r/lK4pF7/1
how it works?
^ asserts the pattern at the begining of the string.
[^\s] negation of \s validates those without an empty string at the begining
[\d\w_-] ensures that body contains only alphanum, _, - no spaces.
{1,10} minimum 1 and maximum 10 mathes, ensures length not greater than 10
$ asserts the pattern at end of string
I'm trying to create a RegEx Validator that checks the file extension in the FileUpload input against a list of allowed extensions (which are user specified). The following is as far as I have got, but I'm struggling with the syntax of the backward slash (\) that appears in the file path. Obviously the below is incorrect because it just escapes the (]) which causes an error. I would be really grateful for any help here. There seems to be a lot of examples out there, but none seem to work when I try them.
[a-zA-Z_-s0-9:\]+(.pdf|.PDF)$
To include a backslash in a character class, you need to use a specific escape sequence (\b):
[a-zA-Z_\s0-9:\b]+(\.pdf|\.PDF)$
Note that this might be a bit confusing, because outside of character classes, \b represents a word boundary. I also assumed, that -s was a typo and should have represented a white space. (otherwise it shouldn't compile, I think)
EDIT: You also need to escape the dots. Otherwise they will be meta character for any character but line breaks.
another EDIT: If you actually DO want to allow hyphens in filenames, you need to put the hyphen at the end of the character class. Like this:
[a-zA-Z_\s0-9:\b-]+(\.pdf|\.PDF)$
You probably want to use something like
[a-zA-Z_0-9\s:\\-]+\.[pP][dD][fF]$
which is same as
[\w\s:\\-]+\.[pP][dD][fF]$
because \w = [a-zA-Z0-9_]
Be sure character - to put as very first or very last item in the [...] list, otherwise it has special meaning for range or characters, such as a-z.
Also \ character has to be escaped by another slash, even inside of [...].
Using ASP.NET syntax for the RegularExpressionValidator control, how do you specify restriction of two consecutive characters, say character 'x'?
You can provide a regex like the following:
(\\w)\\1+
(\\w) will match any word character, and \\1+ will match whatever character was matched with (\\w).
I do not have access to asp.net at the moment, but take this console app as an example:
Console.WriteLine(regex.IsMatch("hello") ? "Not valid" : "Valid"); // Hello contains to consecutive l:s, hence not valid
Console.WriteLine(regex.IsMatch("Bar") ? "Not valid" : "Valid"); // Bar does not contain any consecutive characters, so it's valid
Alexn is right, this is the way you match consecutive characters with a regex, i.e. (a)\1 matches aa.
However, I think this is a case of everything looking like a nail when you're holding a hammer. I would not use regex to validate this input. Rather, I suggest validating this in code (just looping through the string, comparing str[i] and str[i-1], checking for this condition).
This should work:
^((?<char>\w)(?!\k<char>))*$
It matches abc, but not abbc.
The key is to use so called "zero-width negative lookahead assertion" (syntax: (?! subexpression)).
Here we make sure that a group matched with (?<char>\w) is not followed by itself (expressed with (?!\k<char>)).
Note that \w can be replaced with any valid set of characters (\w does not match white-spaces characters).
You can also do it without named group (note that the referenced group has number 2):
^((\w)(?!\2))*$
And its important to start with ^ and end with $ to match the whole text.
If you want to only exclude text with consecutive x characters, you may use this
^((?<char>x)(?!\k<char>)|[^x\W])*$
or without backreferences
^(x(?!x)|[^x\W])*$
All syntax elements for .NET Framework Regular Expressions are explained here.
You can use a regex to validate what's wrong as well as what's right of course. The regex (.)\1 will match any two consecutive characters, so you can just reject any input that gives an IsValid result to that. If this is the only validation you need, I think this way is far easier than trying to come up with a regex to validate correct input instead.
I'm having a hard time trying to create a right regular expression for the RegularExpressionValidator control that allows password to be checked for the following:
- Is greater than seven characters.
- Contains at least one digit.
- Contains at least one special (non-alphanumeric) character.
Cant seem to find any results out there too. Any help would be appreciated! Thanks!
Maybe you will find this article helpful. You may try the following expression
^.*(?=.{8,})(?=.*[\d])(?=.*[\W]).*$
and the breakdown:
(?=.{8,}) - contains at least 8 characters
(?=.*[\d]) - contains at least one digit
(?=.*[\W]) - contains at least one special character
http://msdn.microsoft.com/en-us/library/ms972966.aspx
Search for "Lookaround processing" which is necessary in these examples. You can also test for a range of values by using .{4,8} as in Microsoft's example:
^(?=.*\d).{4,8}$
Try this
((?=.*\d)(?=.*[a-z])(?=.*[\W]).{6,20})
Description of above Regular Expression:
( # Start of group
(?=.*\d) # must contains one digit from 0-9
(?=.*[a-z]) # must contains one lowercase characters
(?=.*[\W]) # must contains at least one special character
. # match anything with previous condition checking
{7,20} # length at least 7 characters and maximum of 20
) # End of group
"/W" will increase the range of characters that can be used for password and pit can be more safe.
Use for Strong password with Uppercase, Lowercase, Numbers, Symbols & At least 8 Characters.
//Code for Validation with regular expression in ASP.Net core.
[RegularExpression(#"^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*[^\da-zA-Z]).{8,15}$")]
Regular expression password validation:
#"^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*[^\da-zA-Z]).{8,15}$"
So, I basically would like to test to see if a string contains a range of alphanumeric characters. It's to be used as a client-side validation and I don't want to prevent users from entering whatever they want. Best to give examples of what should/should not pass validation:
So to be specific, the expression I'm looking for is to test to make sure string contains anywhere from 3 to 10 alphanumeric characters. I'd like to plug into an ASP.NET client side validator.
NOTE: quotes not part of input (but could be!)
" f o o " should pass since there are 3 chars
"f_0_0" should pass
" fo " should not
"F......o......o......b.....a......r" should pass
thx
^([^a-zA-Z0-9]*[a-zA-Z0-9][^a-zA-Z0-9]*){3,10}$
Allows for exactly 3-10 alphanumeric characters, each surrounded by an arbitrary number of non-alphanumeric characters.
(Untested, but it should conform to the JScript subset of the standard .net Regex syntax, as required by the RegularExpressionValidator. Unfortunately, the shorthands \w and \W cannot be used since they include the underscore as an alphanumeric character.)
I'm not familiar with ASP.NET client-side validators, so I'm not sure if you need to do this in a regex, but potentially an easy solution is as follows:
Remove all non-alphanumeric characters (regex replace [^0-9A-Za-z] with nothing).
Check if string length is 3 or greater.