I have a string that sometimes contains a certain substring at the end and sometimes does not. When the string is present I want to update its value. When it is absent I want to add it at the end of the existing string.
For example:
int _newCount = 7;
_myString = 'The count is: COUNT=1;'
_myString2 = 'The count is: '
_rRuleString.replaceAllMapped(RegExp('COUNT=(.*?)\;'), (match) {
//if there is a match (like in _myString) update the count to value of _newCount
//if there is no match (like in _myString2) add COUNT=1; to the string
}
I have tried using a return of:
return "${match.group(1).isEmpty ? _myString + ;COUNT=1;' : 'COUNT=$_newCount;'}";
But it is not working.
Note that replaceAllMatched will only perform a replacement if there is a match, else, there will be no replacement (insertion is still a replacement of an empty string with some string).
Your expected matches are always at the end of the string, and you may leverage this in your current code. You need a regex that optionally matches COUNT= and then some text up to the first ; including the char and then checks if the current position is the end of string.
Then, just follow the logic: if Group 1 is matched, set the new count value, else, add the COUNT=1; string:
The regex is
(COUNT=[^;]*;)?$
See the regex demo.
Details
(COUNT=[^;]*;)? - an optional group 1: COUNT=, any 0 or more chars other than ; and then a ;
$ - end of string.
Dart code:
_myString.replaceFirstMapped(RegExp(r'(COUNT=[^;]*;)?$'), (match) {
return match.group(0).isEmpty ? "COUNT=1;" : "COUNT=$_newCount;" ; }
)
Note the use of replaceFirstMatched, you need to replace only the first match.
Related
I have a SQL sintax in the form of a string in which there are some parameters written in a standard way "<parameter1>, <parameter2>".
Then i have another string with the parameters values written in a standard way as well: "Parameter1=123; Parameter2=aaa".
I need to match the parameters in the first SQL with the values in the second one.
What I have so far:`
Dim BodySQL = "Blablabal WHERE X=<Parameter1> AND Y=<Parameter2>"
Dim vmp As RegularExpressions.MatchCollection = RegularExpressions.Regex.Matches("Parameter1=2555; Parameter2 = 12/02/2021", "([\w ]+)=([\w ]+)")
Dim vmc As RegularExpressions.MatchCollection = RegularExpressions.Regex.Matches(BodySQL, "(?<=\<).+?(?=\>)")
For Each vm As RegularExpressions.Match In vmc
Dim Vl As String = (From m As RegularExpressions.Match In vmp
Where m.Groups(1).Value.Trim = vm.Value.ToString).Select(Of String)(Function(f) f.Groups(2).Value).ElementAt(0).Trim
BodySQL = BodySQL.Replace(vm.Value, Vl)
Next
It works for the first parameter, but then i get
"System.ArgumentOutOfRangeException: 'Specified argument was out of the range of valid values.
Parameter name: index'"
Can I please ask why?
You can extract the keys and values with one regex from the param=value strings, create a dictionary out of them, and then use Regex.Replace to replace the matches with the dictionary values:
Imports System.Text.RegularExpressions
' ...
Dim BodySQL = "Blablabal WHERE X=<Parameter1> AND Y=<Parameter2>"
Dim args As New Dictionary(Of String, String)(StringComparer.InvariantCultureIgnoreCase)
' (StringComparer.InvariantCultureIgnoreCase) makes the dictionary keys case insensitive
For Each match As Match In Regex.Matches("PARAMETER1=2555; Parameter2 = 12/02/2021", "(\S+)\s*=\s*([^;]*[^;\s])")
args.Add(match.Groups(1).Value, match.Groups(2).Value)
Next
Console.WriteLine(Regex.Replace(BodySQL, "<([^<>]*)>",
Function(match)
Return If(args.ContainsKey(match.Groups(1).Value), args(match.Groups(1).Value), match.Value)
End Function))
Output:
Blablabal WHERE X=2555 AND Y=12/02/2021
The (\S+)\s*=\s*([^;]*[^;\s]) pattern matches
(\S+) - captures into Group 1 any one or more non-whitespace chars (the key value)
\s*=\s* - a = char enclosed with zero or more whitespace chars
([^;]*[^;\s]) - Group 2: any zero or more chars other than ; and then one char other than ; and whitespace (the value, it cannot be empty with this pattern. If you want it to be possible to match empty values, you will need to remove [^;\s] and then use Trim() on the match.Groups(2).Value in the code.)
The <([^<>]*)> regex matches
< - a < char (do not escape this char in any regex flavor please, it is never a special regex metachar)
([^<>]*) - Group 1: any zero or more chars other than < and >
> - a literal > char.
Since the key is in Group 1 and < and > on both ends are consumed, the < and > are removed when replacing with the found value.
zero or more chars other than > and < between < and >.
The error is self explanatory. You are trying to access an array or List and specifying an index value that is either negative or larger than the largest index available.
.ElementAt(0) / m.Groups(1) / f.Groups(2)
My guess is that one of them might go out of bounds. Try to debug it with a breakpoint and check the values of your variables.
This is what i did with your code:
Dim vmc = "\<(.*?)\>"
i changed this regex so that it could also give me the "<>"
Dim BodySQL = "Blablabal WHERE X=<Parameter1> AND Y=<Parameter2>"
Dim args As New Dictionary(Of String, String)
For Each match As Match In Regex.Matches("Parameter1=2555; Parameter2 = 12/02/2021", "(\S+)\s*=\s*(\S[^;]+)")
i changed the regex expression to exclude the ";"
args.Add(match.Groups(1).Value, match.Groups(2).Value)
Next
Console.WriteLine(Regex.Replace(BodySQL, vmc,
Function(match As Match)
Return If(args.ContainsKey(match.Groups(1).Value), args(match.Groups(1).Value), match.Value)
End Function))
And now i have what i needed. Thank you a lot :)
Output:
WHERE X = 2555,Y = 12/02/2021
I have a scenario where i want to extract some substring based on following condition.
search for any pattern myvalue=123& , extract myvalue=123
If the "myvalue" present at end of the line without "&", extract myvalue=123
for ex:
The string is abcdmyvalue=123&xyz => the it should return myvalue=123
The string is abcdmyvalue=123 => the it should return myvalue=123
for first scenario it is working for me with following regex - myvalue=(.?(?=[&,""]))
I am looking for how to modify this regex to include my second scenario as well. I am using https://regex101.com/ to test this.
Thanks in Advace!
Some notes about the pattern that you tried
if you want to only match, you can omit the capture group
e* matches 0+ times an e char
the part .*?(?=[&,""]) matches as least chars until it can assert eiter & , or " to the right, so the positive lookahead expects a single char to the right to be present
You could shorten the pattern to a match only, using a negated character class that matches 0+ times any character except a whitespace char or &
myvalue=[^&\s]*
Regex demo
function regex(data) {
var test = data.match(/=(.*)&/);
if (test === null) {
return data.split('=')[1]
} else {
return test[1]
}
}
console.log(regex('abcdmyvalue=123&3e')); //123
console.log(regex('abcdmyvalue=123')); //123
here is your working code if there is no & at end of string it will have null and will go else block there we can simply split the string and get the value, If & is present at the end of string then regex will simply extract the value between = and &
if you want to use existing regex then you can do it like that
var test = data1.match(/=(.*)&|=(.*)/)
const result = test[1] ? test[1] : test[2];
console.log(result);
I'm new to Spark using Scala and I need to replace every nth occurrence of the delimiter with the newline character.
So far, I have been successful at entering a new line after the pipe delimiter.
I'm unable to replace the delimiter itself.
My input string is
val txt = "January|February|March|April|May|June|July|August|September|October|November|December"
println(txt.replaceAll(".\\|", "$0\n"))
The above statement generates the following output.
January|
February|
March|
April|
May|
June|
July|
August|
September|
October|
November|
December
I referred to the suggestion at https://salesforce.stackexchange.com/questions/189923/adding-comma-separator-for-every-nth-character but when I enter the number in the curly braces, I only end up adding the newline after 2 characters after the delimiter.
I'm expecting my output to be as given below.
January|February
March|April
May|June
July|August
September|October
November|December
How do I change my regular expression to get the desired output?
Update:
My friend suggested I try the following statement
println(txt.replaceAll("(.*?\\|){2}", "$0\n"))
and this produced the following output
January|February|
March|April|
May|June|
July|August|
September|October|
November|December
Now I just need to get rid of the pipe symbol at the end of each line.
You want to move the 2nd bar | outside of the capture group.
txt.replaceAll("([^|]+\\|[^|]+)\\|", "$1\n")
//val res0: String =
// January|February
// March|April
// May|June
// July|August
// September|October
// November|December
Regex Explained (regex is not Scala)
( - start a capture group
[^|] - any character as long as it's not the bar | character
[^|]+ - 1 or more of those (any) non-bar chars
\\| - followed by a single bar char |
[^|]+ - followed by 1 or more of any non-bar chars
) - close the capture group
\\| - followed by a single bar char (not in capture group)
"$1\n" - replace the entire matching string with just the first $1 capture group ($0 is the entire matching string) followed by the newline char
UPDATE
For the general case of N repetitions, regex becomes a bit more cumbersome, at least if you're trying to do it with a single regex formula.
The simplest thing to do (not the most efficient but simple to code) is to traverse the String twice.
val n = 5
txt.replaceAll(s"(\\w+\\|){$n}", "$0\n")
.replaceAll("\\|\n", "\n")
//val res0: String =
// January|February|March|April|May
// June|July|August|September|October
// November|December
You could first split the string using '|' to get the array of string and then loop through it to perform the logic you want and get the output as required.
val txt = "January|February|March|April|May|June|July|August|September|October|November|December"
val out = txt.split("\\|")
var output: String = ""
for(i<-0 until out.length -1 by 2){
val ref = out(i) + "|" + out(i+1) + "\n"
output = output + ref
}
val finalout = output.replaceAll("\"\"","") //just to remove the starting double quote
println(finalout)
function getPrecedents(thisFormula){
var exp = /(\w+\!)?\$?[A-Z]{1,}(?:\d+)?(\:?\$?\w+)*(?!\()\b/gm;
var results=[];
var result;
while ((result=exp.exec(thisFormula))!== null){
results.push(result);
}
return results;
}
From the above code I am getting the following results
Trigger_Hires!$AA$15
AD$7
Trigger_Hires!$AC60
Trigger_Hires!$AB60
Rev
Import_Staffing!AD$16
Trigger_Hires!$AC60
Trigger_Hires!$AB60
Customers
Import_Staffing!AD$19
Trigger_Hires!$AC60
I would like to eliminate results that are just letters like Rev and Customers either with modified regexp or 2nd loop
I suggest adding a check before adding the match to the results array:
while (result=exp.exec(thisFormula)) {
if (!/^[A-Za-z]+$/.test(result[0]))
results.push(result[0]);
}
Note you need to access result[0] to get the whole regex match value. To check if the match value is all letters, ^[A-Za-z]+$ regex is used: ^ asserts the position at the start of the string, [A-Za-z]+ matches 1+ letters and $ asserts the position at the end of the string.
i need a regex that replaces everything except the content between the first " and the last ".
I need it like this:
Input String:["Key:"Value""]
And after the regex i only need this:
Output String:Key:"Value"
Thanks!
You can try something like this.
patern:
^.*?"(.*)".*$
Substion:
$1
On Regex101
Explination:
the first part ^.*?" matches as few characters as possible that are between the start of the string and a double quote
the second part(.*)" makes the largest match it can that ends in a double quote, and stuffs it all in a capture group
the last part .*$ grabs what ever is left and includes it in the match
Finally you replace the entire match with the contents of the first capture group
Can you say why you need a RegExp?
A function like:
String unquote(String input) {
int start = input.indexOf('"');
if (start < 0) return input; // or throw.
int end = input.lastIndexOf('"');
if (start == end) return input; // or throw
return input.substring(start + 1, end);
}
is going to be faster and easier to understand than a RegExp.
Anyway, for the challenge, let's say we do want a RegExp that replaces the part up to the first " and from the last " with nothing. That's two replaces, so you can do an
input.replaceAll(RegExp(r'^[^"]*"|"[^"]*$'), "")`
or you can use a capturing group and a computed replacement like:
input.replaceFirstMapped(RegExp(r'^[^"]*"([^]*)"[^"]*$'), (m) => m[1])
Alternatively, you can use the capturing group to select the text between the two and extract it in code, instead of doing string replacement:
String unquote(String input) {
var re = RegExp(r'^[^"]*"([^]*)"[^"]$');
var match = re.firstMatch(input);
if (match == null) return input; // or throw.
return match[1];
}