A weird problem with a regular expression.
The following regular expression
NSString* expression = #"^.*?(\bSKC|CLR|NSC|FEW|SCT|BKN|OVC|VV|CAVOK\b).*?$";
finds the string BKN in expression BKN007 and BKN007CLR002, but does not find the String CAVOK in 110V270 CAVOK 03/M01.
Can someone please help? Thanks!
P.S. The code is in Objective C but I do not think it matters as there is something wrong with the expression itself...
It is probably due to \b after CAVOK which means word boundary.
Try this regex:
NSString* expression = #"^.*?(SKC|CLR|NSC|FEW|SCT|BKN|OVC|VV|CAVOK).*$";
Related
Is it possible to do String comparison where one of the strings I am comparing against has wild cards and is generally just for formatting purposes. For example
Dim correctFormat as String = "##-##-###-##"
Dim stringToCheck = someClass.SomeFunctionThatReturnsAStringToCheck
If FormatOf(CorrectFormat) = FormatOF(StringToCheck) then
Else
End if
I am aware of the made up FormatOf syntax, but I'm just using it to show what I am asking.
No need for regular expressions.
You can simply use the Like operator, which supports ?, * and # as wildcards and also character lists ([...], [!...])
So you simply change your code to:
If stringToCheck Like correctFormat Then
and it will work as expected.
The way is to use regular expressions - that's what they are for.
This is the regular expression that matches the format you have posted:
^\d{2}-\d{2}-\d{3}-\d{2}$
As the previous post mentioned, you should use regular expressions for that purpose - they are way better for that task.
Sadly, learning them can be confusing, especially finding bugs can be really annoying.
I really like http://www.regular-expressions.info/ and http://regexpal.com/ for building and testing regexes before.
In VB.net use something like reg.ismatch
I'm trying to extract multiple parts of a string based on a regular expression like (mymatch1|mymatch2|mymatch3)
I found a function like below, that helps me to extract a match.
NSRange range = [myString rangeOfString:myRegex options:NSRegularExpressionSearch];
But there is any function that can return a set of ranges? or directly the array of substrings matched?
Thanks!
Have you looked at the documentation for NSRegularExpression, methods -[NSRegularExpression enumerateMatchesInString:options:range:usingBlock:]
I have the following regular expression:
WHERE A.srvc_call_id = '40750564' AND REGEXP_LIKE (A.SRVC_CALL_DN, '[^TEST]')
The row that contains 40750564 has "TEST CALL" in the column SRVC_CALL_DN and REGEXP_LIKE doesn't seem to be filtering it out. Whenever I run the query it returns the row when it shouldn't.
Is my regex pattern wrong? Or does SQL not accept [^whatever]?
The carat anchors the expression to the start of a string. By enclosing the letters T, E, S & T in square brackets you're searching, as barsju suggests for any of these characters, not for the string TEST.
You say that SRVC_CALL_DN contains the string 'TEST CALL', but you don't say where in the string. You also say that you're looking for where this string doesn't match. This implies that you want to use not regexp_like(...
Putting all this together I think you need:
AND NOT REGEXP_LIKE (A.SRVC_CALL_DN, '^TEST[[:space:]]CALL')
This excludes every match from your query where the string starts with 'TEST CALL'. However, if this string may be in any position in the column you need to remove the carat - ^.
This also assumes that the string is always in upper case. If it's in mixed case or lower, then you need to change it again. Something like the following:
AND NOT REGEXP_LIKE (upper(A.SRVC_CALL_DN), '^TEST[[:space:]]CALL')
By upper-casing SRV_CALL_DN you ensure that you're always going to match but ensure that your query may not use an index on this column. I wouldn't worry about this particular point as regular expressions queries can be fairly poor at using indexes anyway and it appears as though SRVC_CALL_ID is indexed.
Also if it may not include 'CALL' you will have to remove this. It is best when using regular expressions to make your match pattern as explicit as possible; so include 'CALL' if you can.
Try with '^TEST' or '^TEST.*'
Your regexp means any string not starting with any of the characters: T,E,S,T.
But your case is so simple, starts with TEST. Why not use a simple like:
LIKE 'TEST%'
Does anyone have a good regex to do this? For example:
This is *an* example
should become
This is <b>an</b> example
I need to run this in Objective C, but I can probably work that bit out on my own. It's the regex that's giving me trouble (so rusty...). Here's what I have so far:
s/\*([0-9a-zA-Z ])\*/<b>$1<\/b>/g
But it doesn't seem to be working. Any ideas? Thanks :)
EDIT: Thanks for the answer :) If anyone is wondering what this looks like in Objective-C, using RegexKitLite:
NSString *textWithBoldTags = [inputText stringByReplacingOccurrencesOfRegex:#"\\*([0-9a-zA-Z ]+?)\\*" withString:#"<b>$1<\\/b>"];
EDIT AGAIN: Actually, to encompass more characters for bolding I changed it to this:
NSString *textWithBoldTags = [inputText stringByReplacingOccurrencesOfRegex:#"\\*([^\\*]+?)\\*" withString:#"<b>$1<\\/b>"];
Why don't you just do \*([^*]+)\* and replace it with <b>$1</b> ?
You're only matching one character between the *s. Try this:
s/\*([0-9a-zA-Z ]*?)\*/<b>$1<\/b>/g
or to ensure there's at least one character between the *s:
s/\*([0-9a-zA-Z ]+?)\*/<b>$1<\/b>/g
I wrote a slightly more complex version that ensures the asterisk is always at the boundary so it ignores hanging star characters:
/\*([^\s][^\*]+?[^\s])\*/
Test phrases with which it works and doesn't:
This one regexp works for me (JavaScript)
x.match(/\B\*[^*]+\*\B/g)
I want to have a string in the following format
"FAG001 FAG002 FAG003"
and want to split it into
"FAG001"
"FAG002"
"FAG003"
using a regular expression. Unfortunately my knowledge of regular expression synatax is limited to say teh least. I have tried things like
Dim result = Regex.Split(npcCodes, "([A-Z]3[0-9]3)").ToList
without luck
No need of regex here, you could use String.Split
Dim result As String() = npcCodes.Split(new Char[]{" "})
But if you really want to use regex :
Dim result = Regex.Split(npcCodes, " ").ToList()
As madgnome has pointed out you don't need regular expressions here if the string is always separated with spaces.
However for your information the error you made was that you need curly braces for numeric quantifiers:
[A-Z]{3}
And instead of Regex.Split you can uses Regex.Matches.
The regular expression to use in the Split method would be really simple:
Dim result = Regex.Split(npcCodes, " ").ToList
As the expression only matches a single character, you can just as well use the regular Split method in the String class:
Dim result = npcCodes.Split(" "C).ToList