I have the following string which is legal.
1-5,10-15
Using the following regex, I get a false for match.
^[^-\s]*-?[^-\s]*$
It works fine for things like
1-5,10
1,5
which are all legal. But it won't handle comma delimited ranges. What am I missing?
where's the handling for a comma? try to visualize your regex in regexper
now try this:
^(\d+-?\d+)(?:\,(\d+-?\d+))+$
Update: my regex is not a solution as you might have very specific needs for the captures. However, that nifty tool might help you with the task once you see what your regex does.
Try this pattern,
^\d+(\-\d+)?(\,(\d+(\-\d+)?))*$
it will match on the following strings:
1-5,10-15,5
1,2,3-5,3-4
1-5,10-15
10-15
10-15,5
but not on
1-,10-15,5
1,2,3-5,3-
1-510-15
10-15,
,10-15,5
Screenshot
The best regex I know for splitting comma separated strings is:
",(?=(?:[^\""]*\""[^\""]*\"")*(?![^\""]*\""))"
It will not split an entry in quotations that contains commas.
E.g. Hello, There, "You, People" gives
Hello
There
You, People
^(\s*\d+\s*-?\s*\d*)(\,(\s*\d+\s*-?\s*\d*))*$
It takes care of starting spaces, followed by at least 1 digit. "-" is optional and can be followed by one or more digits. "," is optional and can be followed by the same group as before.
Matches:
1,5
1-5,5-10
15,2,10,4-10
Here's an approach using just splits:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace RangeTester
{
class Program
{
static void Main(string[] args)
{
string str = "1,2,3,1-5,10-15,100-200";
string[] ranges = str.Split(',');
foreach (string range in ranges)
{
Console.WriteLine(GetRange(range.Trim()));
}
Console.Read();
}
static string GetRange(string range)
{
string[] rng = range.Split('-');
if (rng.Length == 2)
return rng[0] + " to " + rng[1];
else
return rng[0];
}
}
}
I was over thinking the solution to this problem, but since you know that your list of numbers/ranges will be first delimited by commas and then by dashes, you can use splits to parse out the individual parts. There is no need to use regular expressions for parsing this string.
Try this regex:
^\d+(-\d+)?(,\d+(-\d+)?)*$
You might want something like (\d+)-(\d+) to get every range. Example here.
I think this should also work fine.
^\d*(-\d*)?,\d*(-?\d*)?$
Hope it helps.
Related
I am trying to get the regex to match only when there is one letter from A-Z followed by a = like this A=, a=, B=, currently it is picking up any number of letters before the = like hem=, ac2=. Usually ^[a-zA-Z] works just fine but its not working for this case since I'm using named capture groups
String pattern = "FL2 (77) Flashing,77,a=1.875,A=90.0,b=3.625,B=95.0,c=1.375,C=175.0,d=2.5,hem=0.5,16GA-AL,";
var regex = new Regex("(?<label>[a-zA-Z]+)=(?<value>[^,]+)");
Other ways I've tried
var regex = new Regex("(?<label>^[a-zA-Z]+)=(?<value>[^,]+)");
var regex = new Regex("(?<label>[^a-zA-Z]+)=(?<value>[^,]+)");
If you want to match l= but not word=, you need a negative look-behind assertion.
new Regex("(?<![a-zA-Z])(?<label>[a-zA-Z])=(?<value>[^,]+)")
If the string pattern you have in your question is really the "haystack" in which you're looking for "needles", a really easy way to solve the problem would be to first split the string on ,, then use RegEx. Then you can use a simpler pattern ^(?<label>[a-zA-Z])=(?<value>.+)$ on each item in the list you get from splitting the string, and only keep the matches.
It's because you have a + after [a-zA-Z], which makes it match one or more characters in that character class. If you remove the +, it will only match one character before the =.
If you want it to only match in situations where there is exactly one alphabetical character before the equals sign, you will want to add to the beginning of the regex to make sure that the character before the letter you want to match is not a letter, like this:
(?<![a-zA-Z])(?<label>[a-zA-Z])=(?<value>[^,]+)
(notice though that this only matters in the case where you don't put a ^ before [a-zA-Z], in the case where you want matches that don't start at the beginning of a line)
Have you tried
var regex = new Regex("(?<label>^[a-zA-Z]?)=(?<value>[^,]+)");
I believe the "+" means 1 or more
"?" means 0 or 1
or exactly 1 should be {1} (at least in python, not sure about C#)
var regex = new Regex("(?<label>^[a-zA-Z]{1})=(?<value>[^,]+)");
Assuming that the label is separated by a comma (which seems to be the case based on your example and code) then you can use:
^|,(?<label>[A-Za-z])=(?<value>[^,]+)
I recommend Regex.Matches over capture groups here:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text.RegularExpressions;
namespace Rextester
{
public class Program
{
public static void Main(string[] args)
{
string content = "FL2 (77) Flashing,77,a=1.875,A=90.0,b=3.625,B=95.0,c=1.375,C=175.0,d=2.5,hem=0.5,16GA-AL,";
const string regexPattern = "(?<=[,| ])[a-zA-Z]=([0-9|.|-])+";
string singleMatch = new Regex(regexPattern).Match(content).ToString();
Console.WriteLine(singleMatch); // a=1.875
MatchCollection matchList = Regex.Matches(content, regexPattern);
var matches = matchList.Cast<Match>().Select(match => match.Value).ToList();
Console.WriteLine(string.Join(", ", matches)); // a=1.875, A=90.0, b=3.625, B=95.0, c=1.375, C=175.0, d=2.5
}
}
}
I want to validate a filename with this format : LetterNumber_Enrollment_YYYYMMDD_HHMM.xml
string filename = "Try123_Enrollment_20130102_1200.xml";
Regex pattern = new Regex(#"[a-zA-z]_Enrollment_[0-9]{6}_[0-9]{4}\\.xml");
if (pattern.IsMatch(filename))
{
return isValid = true;
}
However, I can't make it to work.
Any thing that i missed here?
You are not matching digits at the beginning. Your pattern should be: ^[A-Za-z0-9]+_Enrollment_[0-9]{8}_[0-9]{4}\.xml$ to match given string.
Changes:
Your string starts with alphanumeric string before first _ symbol so you need to check both (letters and digits).
After Environment_ part you have digits with the length of 8 not 6.
No need of double \. You need to escape just dot (i.e. \.).
Demo app:
using System;
using System.Text.RegularExpressions;
class Test {
static void Main() {
string filename = "Try123_Enrollment_20130102_1200.xml";
Regex pattern = new Regex(#"^[A-Za-z0-9]+_Enrollment_[0-9]{8}_[0-9]{4}\.xml$");
if (pattern.IsMatch(filename))
{
Console.WriteLine("Matched");
}
}
}
Your Regex is nowhere near your actual string:
you only match a single letter at the start (and no digits) so Try123 doesn't match
you match 6 digits instead of 8 at the date part so 20130102 doesn't match
you have escaped your backslash near the end (\\.xml) but you've also used # on your string: with # you don't need to escape.
Try this instead:
#"[a-zA-Z]{3}\d{3}_Enrollment_[0-9]{8}_[0-9]{4}\.xml"
I've assumed you want only three letters and three numbers at the start; in fact you may want this:
#"[\w]*_Enrollment_[0-9]{8}_[0-9]{4}\.xml"
You can try the following, it matches letters and digits at the beginning and also ensures that the date is valid.
[A-Za-z0-9]+_Enrollment_(19|20)\d\d(0[1-9]|1[012])(0[1-9]|[12][0-9]|3[01])_[0-9]{4}\.xml
As an aside, to test your regular expressions try the free regular expression designer from Rad Software, I find that it helps me work out complex expressions beforehand.
http://www.radsoftware.com.au/regexdesigner/
My brain must be frazzled but I can't get this to work and I've very little experience with regular expressions.
I have a string such as "gfdsgfd354gfdgfd55gfdgfdgfs9gfdgsf".
I need a regular expression to find the last digit in the string - in this case the "9".
EDIT
I should have been clearer but, as I say, I'm frazzled.
It's to insert a hyphen character before the final digit. I'm using C# Regex.Replace. Using the idea already suggested by Dave Sexton I tried the following without success:
private string InsertFinalDigitHyphen(string data)
{
return Regex.Replace(data, #"(\d)[^\d]*$", " $1");
}
With this I can process "ABCDE1FGH" with the intention of getting "ABCDE-1FGH" but I actually get "ABCDE-1".
I always find regular expressions hard to read, so you could do it in an alternative way with the following LINQ statement:
string str = "gfdsgfd354gfdgfd55gfdgfdgfs9gfdgsf";
var lastDigit = str.Last(char.IsDigit);
Output:
9
To insert a hyphen before this one, you can use LastIndexOf instead of Last and use that index to insert the hyphen at the correct location in the string.
You can use this one :
(\d)[^\d]*$
EDIT :
You initially mentioned only a match, no language and no replacement. For your C# replacement, you should use
private string InsertFinalDigitHyphen(string data) {
return Regex.Replace(data, #"(\d)(\D*)$", " $1$2");
}
If it is the last single digit you want the use this:
(\d)[^\d]*$
If it is the last set of digits then use this:
(\d+)[^\d]*$
EDIT:
You need to pick out the capture group (the bit in the brackets) - for c# I think it would be something like this:
Regex.Matches("gfdsgfd354gfdgfd55gfdgfdgfs9gfdgsf", '(\d)[^\d]+$')[0].Groups[1].Captures[0].Value
Or alternatively to avoid capture groups you could use a look behind regex like so:
\d(?=[^\d]+$)
You can also do this with String.LastIndexOfAny:
private string InsertFinalDigitHyphen(string data)
{
int lastDigit = data.LastIndexOfAny(new char[] {'0','1','2','3','4','5','6','7','8','9']);
return (lastDigit == -1) ? data : data.Insert(lastDigit, "-");
}
Is there a way to convert string without spaces to a proper sentence??
E.g. "WhoAmI" needs to be converted to "Who Am I"
A regex replacement would do this, if you're just talking about inserting a space before each capital letter:
using System;
using System.Text.RegularExpressions;
class Test
{
static void Main()
{
var input = "WhoAmI";
var output = Regex.Replace(input, #"\p{Lu}", " $0").TrimStart();
Console.WriteLine(output);
}
}
However, I suspect there will be significant corner cases. Note that the above uses \p{Lu} instead of just [A-Z] to cope with non-ASCII capital letters; you may find A-Z simpler if you only need to deal with ASCII. The TrimStart() call is to remove the leading space you'd get otherwise.
If every word in the string is starting with uppercase you may just convert each part that is starting with uppercase to a space separated string.
You can use LINQ
string words = "WhoAmI";
string sentence = String.Concat(words.Select(letter => Char.IsUpper(letter) ? " " + letter
: letter.ToString()))
.TrimStart();
Sorry guys, it seems like I didn't explain my question clearly. Please allow me to rephrase my question again.
I use WebClient to download the whole webpage and I got the content as a string
"
.......
.....
var picArr ="/d/manhua/naruto/516/1.png|/d/manhua/naruto/516/2.png|/d/manhua/naruto/516/3.png|/d/manhua/naruto/516/4.png|/d/manhua/naruto/516/5.png|/d/manhua/naruto/516/6.png|/d/manhua/naruto/516/7.png|/d/manhua/naruto/516/8.png|/d/manhua/naruto/516/9.png|/d/manhua/naruto/516/10.png|/d/manhua/naruto/516/11.png|/d/manhua/naruto/516/12.png|/d/manhua/naruto/516/13.png|/d/manhua/naruto/516/14.png|/d/manhua/naruto/516/15.png|/d/manhua/naruto/516/16.png"
......
";
in this content, I want to get only one line which is
var picArr ="/d/manhua/naruto/516/1.png|/d/manhua/naruto/516/2.png|/d/manhua/naruto/516/3.png|/d/manhua/naruto/516/4.png|/d/manhua/naruto/516/5.png|/d/manhua/naruto/516/6.png|/d/manhua/naruto/516/7.png|/d/manhua/naruto/516/8.png|/d/manhua/naruto/516/9.png|/d/manhua/naruto/516/10.png|/d/manhua/naruto/516/11.png|/d/manhua/naruto/516/12.png|/d/manhua/naruto/516/13.png|/d/manhua/naruto/516/14.png|/d/manhua/naruto/516/15.png|/d/manhua/naruto/516/16.png"
now I want use regular expression to get this string and get the value of picArr.
my reg exp is
var picArr ="([.]*)"
I think the dot means any characters. But it doesn't work. :(
Any idea?
THanks a lot
/picArr =\"([^\"]+)\"/
If I got this right that's what you need.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
namespace ExtractFileNames
{
class Program
{
static void Main(string[] args)
{
string pageData = #"blah blah
var picArr =""/d/manhua/naruto/516/1.png|/d/manhua/naruto/516/2.png|/d/manhua/naruto/516/3.png|/d/manhua/naruto/516/4.png|/d/manhua/naruto/516/5.png|/d/manhua/naruto/516/6.png|/d/manhua/naruto/516/7.png|/d/manhua/naruto/516/8.png|/d/manhua/naruto/516/9.png|/d/manhua/naruto/516/10.png|/d/manhua/naruto/516/11.png|/d/manhua/naruto/516/12.png|/d/manhua/naruto/516/13.png|/d/manhua/naruto/516/14.png|/d/manhua/naruto/516/15.png|/d/manhua/naruto/516/16.png""
more blah decimal blah";
var match = Regex.Match(pageData, #"var\s+picArr\s*=\s*""(.*?)""");
var str = match.Groups[1].Value;
var files = str.Split('|');
foreach(var f in files)
{
Console.WriteLine(f);
}
Console.ReadLine();
}
}
}
Output:
/d/manhua/naruto/516/1.png
/d/manhua/naruto/516/2.png
/d/manhua/naruto/516/3.png
/d/manhua/naruto/516/4.png
/d/manhua/naruto/516/5.png
/d/manhua/naruto/516/6.png
/d/manhua/naruto/516/7.png
/d/manhua/naruto/516/8.png
/d/manhua/naruto/516/9.png
/d/manhua/naruto/516/10.png
/d/manhua/naruto/516/11.png
/d/manhua/naruto/516/12.png
/d/manhua/naruto/516/13.png
/d/manhua/naruto/516/14.png
/d/manhua/naruto/516/15.png
/d/manhua/naruto/516/16.png
If you just want to get the filenames, you could just do a split on the pipe:
var picArr = "/d/manhua/naruto/516/1.png|/d/manhua/naruto/516/2.png|/d/manhua/naruto/516/3.png|/d/manhua/naruto/516/4.png|/d/manhua/naruto/516/5.png|/d/manhua/naruto/516/6.png|/d/manhua/naruto/516/7.png|/d/manhua/naruto/516/8.png|/d/manhua/naruto/516/9.png|/d/manhua/naruto/516/10.png|/d/manhua/naruto/516/11.png|/d/manhua/naruto/516/12.png|/d/manhua/naruto/516/13.png|/d/manhua/naruto/516/14.png|/d/manhua/naruto/516/15.png|/d/manhua/naruto/516/16.png";
var splitPics = picArr.Split('|');
foreach (var pic in splitPics)
{
Console.WriteLine(pic);
}
It looks like you want the value of the string literal in your snippet, "/d/manhua/naruto/516/1.png|..."
Get rid of the square brackets. "." matches any character just as it is, without brackets. Square brackets are for matching a limited set of characters: For example, you'd use "[abc]" to match any "a", "b", or "c".
It looks like the brackets have the effect of escaping the ".", a feature I hadn't known about (or forgot, sometime in the Ordovician). But I tested the regex as you have it with the string value replaced with a series of dots, and the regex matched. It's being treated as a literal "." character, which you would more likely try to match with a backslash escape: "\."
So just get rid of the brackets and it should work. It works in VS2008 for me.