Basically I'm trying to code a regex that will accept two words and nothing else, the words can contain any letters, but not numbers.
I've currently got:
^[a-zA-Z+#-.0-9]/s^[a-zA-Z+#-.0-9]$
Although I know for sure this is wrong because it isn't allowing two words separated by a space, it also currently allows numbers.
Does anybody know what Regex code I need to get this working?
This should do the trick! :)
//Allow letters and numbers
^\w+\s\w+$
//Allow only letters
^[a-zA-Z]+\s+[a-zA-Z]+$
While something using the \w shorthand character class might work for you, you specifically wrote can contain any letters, but not numbers, so you'd have to use:
^[a-zA-Z]+\s+[a-zA-Z]+$
Your expression allows numbers (and + and any of these characters: #$%&*()-',.) because you included all of these characters in your character class [a-zA-Z+#-.0-9], which means lowercase and uppercase letters, + sign, any ASCII characters from # to . (which includes $%&*()-',), and any numbers 0-9.
The shorthand character class \w allows letters, numbers, and underscore (_)
I might recommend running through a short tutorial on regex before deciding its the solution for you...
How about something like:
^\w+\s+\w+$
Related
http://regexr.com/3ars8
^(?=.*[0-9])(?=.*[A-z])[0-9A-z-]{17}$
Should match "17 alphanumeric chars, hyphens allowed too, must include at least one letter and at least one number"
It'll correctly match:
ABCDF31U100027743
and correctly decline to match:
AB$DF31U100027743
(and almost any other non-alphanumeric char)
but will apparently allow:
AB^DF31U100027743
Because your character class [A-z] matches this symbol.
[A-z] matches [, \, ], ^, _, `, and the English letters.
Actually, it is a common mistake. You should use [a-zA-Z] instead to only allow English letters.
Here is a visualization from Expresso, showing what the range [A-z] actually covers:
So, this regex (with i option) won't capture your string.
^(?=.*[0-9])(?=.*[a-z])[0-9a-z-]{17}$
In my opinion, it is always safer to use Ignorecase option to avoid such an issue and shorten the regex.
regex uses ASCII printable characters from the space to the tilde range.
Whenever we use [A-z] token it matches the following table highlighted characters. If we use [ -~] token it matches starting from SPACE to tilde.
You're allowing A-z (capital 'A' through lower 'z'). You don't say what regex package you're using, but it's not necessarily clear that A-Z and a-z are contiguous; there could be other characters in between. Try this instead:
^(?=.*[0-9])(?=.*[A-Za-z])[0-9A-Za-z-]{17}$
It seems to meet your criteria for me in regexpal.
The goal is to remove all non-capital letter in a string and I managed to find a regular expression solution without fully understanding it.
> gsub("[^::A-Z::]","", "PendingApproved")
[1] "PA"
I tried to read the documentation of regex in R but the double colon isn't really covered there.
[]includes characters to match in regex, A-Z means upper case and ^ means not, can someone help me understand what are the double colons there?
As far as I know, you don't need those double colons:
gsub("[^A-Z]", "", "PendingApproved")
[1] "PA"
Your current pattern says to remove any character which is not A-Z or colon :. The fact that you repeat the colons twice, on each side of the character range, does not add any extra logic.
Perhaps the author of the code you are using confounded the double colons with R's regex own syntax for named character classes. For example, we could have written the above as:
gsub("[^[:upper:]]","", "PendingApproved")
where [:upper:] means all upper case letters.
Demo
To remove all small letters use following:
gsub("[a-z]","", "PendingApproved")
^ denotes only starting characters so
gsub("^[a-z]","", "PendingApproved")
will not remove any letters from your tested string because your string don't have any small letters in starting of it.
EDIT: As per Tim's comment adding negation's work in character class too here. So let's say we want to remove all digits in a given value among alphabets and digits then following may help.
gsub("[^[:alpha:]]","", "PendingApproved1213133")
Where it is telling gsub then DO NOT substitute alphabets in this process. ^ works as negation in character class.
We can use str_remove from stringr
library(stringr)
str_remove_all("PendingApproved", "[a-z]+")
#[1] "PA"
Right now I need to duplicate a password expression validator for a website. The password is only required to be 8-25 characters (only alphabet characters) long. I thought this was weird and had been using this regex
(?!^[0-9]*$)(?!^[a-zA-Z]*$)^([a-zA-Z0-9]{8,25})
but it has to be optional to have a capital letter, special characters and/or numbers throughout the password. I'm not particularly apt at building regex's where there are optional characters. Any help would be be appreciated.
I am using asp.net's RegularExpressionValidator.
This pattern should work:
^[a-zA-Z]{8,25}$
It matches a string consisting of 8 to 25 Latin letters.
If you want to allow numbers as well, this pattern should work:
^[a-zA-Z0-9]{8,25}$
It matches a string consisting of 8 to 25 Latin letters or decimal digits.
If you want to allow special characters as well, this pattern should work:
^[a-zA-Z0-9$#!]{8,25}$
It matches a string consisting of 8 to 25 Latin letters, decimal digits, or symbols, $, # or ! (of course you can add to this set fairly easily).
Your current regex won't work because it will accept special characters as from 9th character (and anything after the 9th character in fact, even a 26th character because you don't have the end of string anchor) .
You probably want something like this:
^(?=.*[a-z])[A-Za-z0-9]{8,25}$
This first makes sure there are lowercase alphabets (you mentioned that uppercase and digits are optional, so this makes obligatory lowercase) and then allows only uppercase and digits.
EDIT: To allow any special characters, you can use this:
^(?=.*[a-z]).{8,25}$
My understanding of your problem is that the password's first requirement is that it has to contain lowercase alphabet characters. The option now is that it can also contain other characters. If this isn't right, let me know.
regex101 demo
I've a textbox in an ASP.NET application, for which I need to use a regular expression to validate the user input string. Requirements for regex are -
It should allow only one space between words. That is, total number of spaces between words or characters should only be one.
It should ignore leading and trailing spaces.
Matches:
Test
Test abc
Non Matches:
Test abc def
Test abc --> I wanted to include multiple spaces between the 2 words. However the editor ignores these extra spaces while posting a question.
Assuming there must be either one or two 'words' (i.e. sequences of non-space characters)
"\s*\S+(\s\S+)?\s*"
Change \S to [A-Za-z] if you want to allow only letters.
Pretty straightforward:
/^ *(\w+ ?)+ *$/
Fiddle: http://refiddle.com/gls
Maybe this one will do?
\s*\S+?\s?\S*\s*
Edit: Its a server-encoded regex, meaning that you might need to remove one of those escaping slashes.
How about:
^\s*(\w+\s)*\w+\s*$
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.