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
Related
I have an Asp.Net script which includes a validator like this:
<asp:RegularExpressionValidator ID="AdvNeedIdValidator" runat="server"
ControlToValidate="NEEDS" ErrorMessage="Need ID is numeric."
ForeColor="Red" ValidationExpression="^\d*\.?\d*$">*</asp:RegularExpressionValidator>
The validator is supposed to reject non-numeric inputs (NEEDS is a numeric value) but I think there is problem with the regular expression "^\d*\.?\d*$" because when I want to clear the Input text the when the user enter the text the ErrorMessage pops up. I have a NeedID field with 4 number numeric value,so can you please let me know how I can upgrade the "^\d*\.?\d*$" to get rid of that Issue?
Thanks
If you simply want to validate a 4 digit whole number, try using the following:
^\d{4}$
^\d means start with any digit
{4} means there must be exactly 4.
$ means that is the end of the pattern.
So in other words, the regex validates and expression of exactly 4 digits.
If you're looking to validate numbers such as:
500.40
30
0.02
.02
this should meet what you're looking for:
"\d*\.?\d+"
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!
I have a regular expression validator on a text box to validate that the text entered is a valid date.
See reg ex below:
ValidationExpression="^[0-9]{1,2}/[0-9]{1,2}/[0-9]{4}$"
Now I want to allow the following in the textbox: mm/dd/yyyy
How can I update my regex so that if mm/dd/yyyy is entered it does not throw a validation error?
Thanks in advance.
ValidationExpression="^[0-9m]{1,2}/[0-9d]{1,2}/[0-9y]{4}$"
Basically allows 0-9 or m in the first field, 0-9 or d in the second, 0-9 or y in the third (in regular expression [] brackets contain a list of possible options, - denote ranges of values when placed within brackets).
This is a more accurate way to restrict the Date to a more meaningful format
^[1-12]{1,2}/[1-31]{1,2}/[2000-2050,1900-1999]{4}$
This is still not perfect as this will allow - for instance - a date 02/31/2013.
Just realized this is quiet buggy.
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}$")]
Regular expression password validation:
#"^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*[^\da-zA-Z]).{8,15}$"