Coming from perl, I'm I bit confused by the asp.net regex classes.
I have a simple pattern I'm trying to match: "number text number"
My code looks like:
Match results = Regex.Match(mystring, #"(\d+)\s+(Highway|Hwy|Route|Rte)\s+(\d+)",RegexOptions.IgnoreCase);
foreach (Group g in results.Groups)
{
string token = g.Value;
}
The problem is that the groups seems to contain 4 results, not the 3 I would expect - the first is the entire string that gets matched, while the next 3 are what I would expect.
Is there a simple way to directly access my 3 results?
You could use Matches:
// Define a test string.
string text = "The the quick brown fox fox jumped over the lazy dog dog.";
// Find matches.
MatchCollection matches = rx.Matches(text);
// Report the number of matches found.
Console.WriteLine("{0} matches found in:\n {1}",
matches.Count,
text);
// Report on each match.
foreach (Match match in matches)
{
...
}
var results = Regex.Match("55 Hwy 66", #"(\d+)\s+(Highway|Hwy|Route|Rte)\s+(\d+)", RegexOptions.IgnoreCase).Groups.OfType<Group>().Select((name, index) => new {name, index}).Where(x => x.index > 0).Select(x => x.name).ToList();
This is just a case of how it is designed to work, and it is just a case of ignoring the first match. I do agree that it is a strange implementation and not how I would have expected it to work.
If the regular expression engine can find a match, the first element of the GroupCollection object returned by the Groups property contains a string that matches the entire regular expression pattern.
Taken from here
I know this is an old question, but I ended up here through a search confirming my own thoughts and there was no definitive answer.
Related
I need a regex which validate string of numbers either math "aabb" or "abba" pattern.
For example: both 1122 or 1221 is valid
Regex for both "aabb", "abba" worked fine alone.
But when i'm trying to combine "aabb" OR "abba", the result of "aabb" is always false.
(1122 returned not valid)
Here is my implementation in C#:
string phoneNumber = "1221"; // "1122" failed
Dictionary<string, string> subPatterns = new Dictionary<string, string>();
subPatterns[#"(\d)(\d)\2\1$"] = "abba";
subPatterns[#"(\d)\1(\d)\2$"] = "aabb";
string pattern = string.Join("|", subPatterns.Select(e => e.Key));
foreach (Match m in Regex.Matches(phoneNumber, pattern))
{
if (m.Success)
{
Console.WriteLine("TRUE");
}
}
Did i missed something?
The alternation changes the capture group numbers. You can either account for the incremented numbers in the alternation:
subPatterns[#"(\d)(\d)\2\1$"] = "abba";
subPatterns[#"(\d)\3(\d)\4$"] = "aabb";
The pattern will look like this, matching the 4 digits at the end of the string due to the $
(\d)(\d)\2\1$|(\d)\3(\d)\4$
Or you can use the same named backreferences:
subPatterns[#"(?<1>\d)\k<1>(?<2>\d)\k<2>"] = "abba";
subPatterns[#"(?<1>\d)(?<2>\d)\k<2>\k<1>"] = "aabb";
The pattern will then look like
(?<1>\d)(?<2>\d)\k<2>\k<1>|(?<1>\d)\k<1>(?<2>\d)\k<2>
Note that if the matches are for the whole line, you can append an anchor ^ to it and the whole pattern will look like
^(?:(?<1>\d)(?<2>\d)\k<2>\k<1>|(?<1>\d)\k<1>(?<2>\d)\k<2>)$
See a regex demo and a C# demo.
// I have a custom metadata object named boatNames__mdt and I'm using two methods to get a list of picklist values in a String[];
First Method
Map<String, boatNames__mdt> mapEd = boatNames__mdt.getAll();
string boatTypes = (string) mapEd.values()[0].BoatPick__c;
// BoatPick__c is a textarea field (Eg: 'Yacht, Sailboat')
string[] btWRAP = new string[]{};
**btWRAP**.addAll(boatTypes.normalizeSpace().split(','));
Second Method
string[] strL = new string[]{};
Schema.DescribeFieldResult dfr = Schema.SObjectType.boatNames__mdt.fields.BoatTypesPicklist__c;
// BoatTypesPicklist__c is a picklist field (Picklist Values: 'Yacht, Sailboat')
PicklistEntry[] picklistValues = dfr.getPicklistValues();
for (PicklistEntry pick : picklistValues){
**strl**.add((string) pick.getLabel());
}
Map with SOQL query
Map<Id, BoatType__c> boatMap = new Map<Id, BoatType__c>
([Select Id, Name from BoatType__c Where Name in :btWRAP]);
When I run the above Map with SOQL query(btWRAP[]) no records show up.
But when I used it using the strl[] records do show up.
I'm stunned!
Can you please explain why two identical String[] when used in exact SOQL queries behave so different?
You are comparing different things so you get different results. Multiple fails here.
mapEd.values()[0].BoatPick__c - this takes 1st element. At random. Are you sure you have only 1 element in there? You might be getting random results, good luck debugging.
normalizeSpace() and trim() - you trim the string but after splitting you don't trim the components. You don't have Sailboat, you have {space}Sailboat
String s = 'Yacht, Sailboat';
List<String> tokens = s.normalizeSpace().split(',');
System.debug(tokens.size()); // "2"
System.debug(tokens); // "(Yacht, Sailboat)", note the extra space
System.debug(tokens[1].charAt(0)); // "32", space's ASCII number
Try splitting by "comma, optionally followed by space/tab/newline/any other whitespace symbol": s.split(',\\s*'); or call normalize in a loop over the split's results?
pick.getLabel() - in code never compare using picklist labels unless you really know what you're doing. Somebody will translate the org to German, French etc and your code will break. Compare to getValue()
what is wrong with this code?
bool claimExists;
string currentClaimControlNo = "700209308399870";
List<string> claimControlNo = new List<string>();
claimControlNo.Add("700209308399870");
if (claimControlNo.Contains(currentClaimControlNo.Substring(0, 14)))
claimExists = true;
else
claimExists = false;
Why the claimControlNo above is coming into false?
Since I know the value exists, how can i tune the code?
It's reporting false because you aren't asking whether the list contains the currentClaimControlNo, you're asking whether it contains a string that is the first fourteen characters of the fifteen-character string currentClaimControlNo.
Try this instead:
claimExists = claimControlNo.Any(ccn => ccn.StartsWith(currentClaimControlNo.Substring(0,14)));
Your count is wrong. There are 15 characters. Your substring is cutting off the last 0 which fails the condition.
Because you're shaving off the last digit in your substring.
if you change the line
if (claimControlNo.Contains(currentClaimControlNo.Substring(0, 14)))
to
if (claimControlNo.Contains(currentClaimControlNo.Substring(0, 15)))
it works.
Because contains on a list looks for the whole item, not a substring:
currentClaimControlNo.Substring(0, 14)
"70020930839987"
Is not the same as
700209308399870
You're missing a digit, hence why your list search is failing.
I think you are trying to find something in the list that contains that substring. Don't use the lists contain method. If you are trying to find something in the list that has the subset do this
claimExists = claimControlNo.Any(item => item.Contains(currentClaimControlNo.Substring(0, 14)))
This goes through each item in claimControlNo and each item can then check if it contains the substring.
Why do it this way? The Contains method on a string
Returns a value indicating whether the specified System.String object occurs within this string.
Which is what you want.
Contains on a list, however
Determines whether an element is in the System.Collections.Generic.List.
They aren't the same, hence your confusion
Do you really need this explaining?
You are calling Substring for 14 characters when the string is of length 15. Then you are checking if your list (which only has one item of length 15) contains an item of length 14. It doesn;t event need to check the value, the length is enough to determine it is not a match.
The solution of course is to not do the Substring, it makes not sense.
Which would look like this:
if (claimControlNo.Contains(currentClaimControlNo))
claimExists = true;
else
claimExists = false;
Then again, perhaps you know you are trimming the search, and are in fact looking for anything that has a partial match within the list?
If this is the case, then you can simply loop the list and do a Contains on each item. Something like this:
bool claimExists = false;
string searchString = currentClaimControlNo.Substring(0, 14);
foreach(var s in claimControlNo)
{
if(s.Contains(searchString))
{
claimExists = true;
break;
}
}
Or use some slightly complex (certainly more complex then I can remember off the top of my head) LINQ query. Quick guess (it's probably right to be fair, I am pretty freaking awesome):
bool claimExists = claimControlNo.Any(x => x.Contains(searchString));
Check it:
// str will be equal to 70020930839987
var str = currentClaimControlNo.Substring(0, 14);
List<string> claimControlNo = new List<string>();
claimControlNo.Add("700209308399870");
The value str isn't contained in the list.
I'm using a linq query where i do something liike this:
viewModel.REGISTRATIONGRPS = (From a In db.TABLEA
Select New SubViewModel With {
.SOMEVALUE1 = a.SOMEVALUE1,
...
...
.SOMEVALUE2 = If(commaseparatedstring.Contains(a.SOMEVALUE1), True, False)
}).ToList()
Now my Problem is that this does'n search for words but for substrings so for example:
commaseparatedstring = "EWM,KI,KP"
SOMEVALUE1 = "EW"
It returns true because it's contained in EWM?
What i would need is to find words (not containing substrings) in the comma separated string!
Option 1: Regular Expressions
Regex.IsMatch(commaseparatedstring, #"\b" + Regex.Escape(a.SOMEVALUE1) + #"\b")
The \b parts are called "word boundaries" and tell the regex engine that you are looking for a "full word". The Regex.Escape(...) ensures that the regex engine will not try to interpret "special characters" in the text you are trying to match. For example, if you are trying to match "one+two", the Regex.Escape method will return "one\+two".
Also, be sure to include the System.Text.RegularExpressions at the top of your code file.
See Regex.IsMatch Method (String, String) on MSDN for more information.
Option 2: Split the String
You could also try splitting the string which would be a bit simpler, though probably less efficient.
commaseparatedstring.Split(new Char[] { ',' }).Contains( a.SOMEVALUE1 )
what about:
- separating the commaseparatedstring by comma
- calling equals() on each substring instead of contains() on whole thing?
.SOMEVALUE2 = If(commaseparatedstring.Split(',').Contains(a.SOMEVALUE1), True, False)
I am working in C# with ASP.NET. I am familiar with this error but this time I can't solve it.
I have text in a drop-down list like this:
राम कुमार सिंह 8s2w8r
here राम कुमार सिंह is the name in HINDI while 8s2w8r is users' ID.
I need to separate these two values and need to pass them as session variables. The logic I am using is depicted in the code.
public string reverse(string s)
{
char []temp=s.ToCharArray();
Array.Reverse(temp);
return (temp.ToString());
}
string dropdowntextreversed=reverse(DropDownList1.Text);
char []delim=new char[]{' '};
string []parts=dropdowntextreversed.Split(delim,2);
string family_head_uid = reverse(parts[0]);
string family_head = reverse(parts[1]);
Session.Add("family_head", family_head);
Session.Add("family_head_uid", family_head_uid);
Response.Redirect("/WebForm1.aspx");
I always get an error as the index was outside the bounds of the array! I don't understand this because I am breaking the string into 2 parts so it should have parts[0] and parts[1]. Please suggest...
You are splitting the string into MAXIMUM 2 parts, but if there's only one you will get probably one part.
Read this documentation
Try to assert that parts.Length is == 2 or to access elemnts only there atre two elements
Try this link. As I think there is a problem in the temp.ToString() which will return System.Char[] rather than the value which are you looking for. Use string.join instead will work.
Use the following reverse method:
public string reverse(string s)
{
return String.Join(String.Empty, s.ToCharArray().Reverse());
}