Regular Expression to limit string length - asp.net

I have an issue where I need to use a RegularExpressionValidator to limit the length of a string to 400 Characters.
My expression was .{0,400}
My question: Is there a way to limit the length of characters to 400 without taking into consideration blank spaces?
I want to be able to accept blank spaces in the string but not count it in the length. Is this possible?

I pretty much agree with Greg, but here's the regex you want:
^\s*([^\s]\s*){0,400}$
#Boopid: If you really meant only the space character, replace \s with a space in the regex.

It sounds like you might want to write your own validator class instead of using the RegularExpressionValidator. Regular expressions certainly have their uses, but this doesn't sound like one of them.
Your custom validator could remove all the spaces, then check the length of the string. Ultimately, the code will be more readable than a regular expression that does the same thing.

Related

Textboxvalidation: Empty or minimum 3 characters (spaces do not count)

I have some textboxes I'm using as search-fields.
The textbox can be empty, but when a search-criteria is filled in, it must be at least 3 characters long, ignoring the spaces in the count.
I've found that a regularexpressionvalidator validates true when the textbox is empty, so that part is ok.
Q: regex for a minimumlenth of 3 characters. Spaces are allowed, but should not count in the length.
Thanks.
Have you tried something like this?
'(\s*\w\s*){3}'
This regular expression looks for a character (\w) optionally surronded by any whitespace (\s*) three times ({3}), which is what you're looking for.
Note: I don't know asp.net, but I think the regular expression is all you need to solve the problem.

Regular Expression Validator for Letters and Numbers only

What is the Regular Expression Validator for only Letters and Numbers in asp.net?
I need to enter only 0-9,a-z and A-Z. I don't want to allow any special characters single or double quotes etc. I am using asp.net 3.5 framework.
I tried ^[a-zA-Z0-9]+$ and ^[a-zA-Z0-9]*$. They are not working.
Any help will be appreciated.
Try the following.
^[a-zA-Z0-9]+$
go to this example and also alphanumerics for more
then try this
^[a-zA-Z0-9]*$
If length restriction is necessary use
^[a-zA-Z0-9]{0,50}$
This will match alphanumeric strings of 0 to 50 chars.
you can try this....
^[a-zA-Z0-9]+$
see more info at here
You can define a regular expression as follows,
Regex myRegularExpression = new Regex(" \b^[a-zA-Z0-9]+$\b");
be sure to include System.Text.RegularExpression
and then use the Regex to match it with your user-control as follows,
eg : if your user-control is a textbox
myRegularExpression.isMatch(myTextBox.Text);
Dear English speaking people. With all due respect. A-Z are not the only letters in the world. Please use \w instead of [A-Za-z0-9] if you support other languages in your apps

Regular Expression for username and password?

I am trying to use a regular expression for name field in the asp.net application.
Conditions:name should be minimum 6 characters ?
I tried the following
"^(?=.*\d).{6}$"
I m completely new to the regex.Can any one suggest me what must be the regex for such condition ?
You could use this to match any alphanumeric character in length of 6 or more: ^[a-zA-Z0-9]{6,}$. You can tweak it to allow other characters or go the other route and just put in exclusions. The Regex Coach is a great environment for testing/playing with regular expressions (I wrote a blog post with some links to other tools too).
Look at Expression library and choose user name and/or password regex for you. You can also test your regex in online regex testers like RegexPlanet.
My regex suggestions are:
^[a-zA-Z][a-zA-Z0-9._\-]{5,}$
This regex accepts user names with minimum 6 characters, starting with a letter and containing only letters, numbers and ".","-","_" characters.
Next one:
^[a-zA-Z0-9._\\-]{6,}$
Similar to above, but accepts ".", "-", "_" and 0-9 to be first characters too.
If you want to validate only string length (minimum 6 characters), this simple regex below will be enough:
^.{6,}$
What about
^.{6,}$
What's all the stuff at the start of yours, and did you want to limit yourself to digits?
NRegex is a nice site for testing out regexes.
To just match 6 characters, ".{6}" is enough
In its simplest form, you can use the following:
.{6,}
This will match on 6 or more characters and fail on anything less. This will accept ANY character - unicode, ascii, whatever you are running through. If you have more requirements (i.e. only the latin alphabet, must contain a number, etc), the regex would obviously have to change.

Difference between (.|[\r\n]){1,1500} and ^.{1,1500}$

What is the difference between below two regular expressions
(.|[\r\n]){1,1500}
^.{1,1500}$
The first matches up-to-1500 chars, and the second (assuming you haven't set certain regex options) matches a first single line of up-to-1500 chars, with no newlines.
. does not match new lines.
The second one matches the first 1500 characteres of a line IF the line contains 1500 characters or less
First expression matches some <= 1500 characters of the file(or other source).
Second expression matches a entire line with charsNumber <= 1500.
. matches any character except \n newline.
If it's for use in a RegularExpressionValidator, you probably want to use this regex:
^[\s\S]{1,1500}$
This is because the regex may be run on either the server (.NET) or the client (JavaScript). In .NET regexes you can use the RegexOptions.Singleline flag (or its inline equivalent, (?s)) to make the dot match newlines, but JavaScript has no such mechanism.
[\s\S] matches any whitespace character or anything that's not a whitespace character--in other words, anything. It's the most popular idiom for matching anything including a newline in JavaScript; it's much, much more efficient than alternation-based approaches like (.|\n).
Note that you'll still need to use a RequiredFieldValidator if you don't want the user to leave the textbox empty.

Don't want spaces in the text, but this regex is passing not sure why

I am using the following regex
/[a-zA-Z0-9]+/i.test(value)
If I enter a space in the word, it passes.
I don't see where spaces are aloud in the regex, why is it passing?
You need to set the beginning and end bounderies so that the entire string must match the regular expression, otherwise it'll look for any match (which in this case is one or more of the characters specified).
Try this:
/^[a-zA-Z0-9]+$/i.test(value)
Because you haven't anchored it.
For these sorts of tests, it's typically safer to make sure you don't have the negated character class:
/[^a-zA-Z0-9]/

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