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How to check Equal Sign in string using REGEX in C#

I want to check string which look like following
1st radius = 120
and
2nd radius = 'value'
Here is my code
v1 = new Regex(#"^[A-Za-z]+\s[=]\s[A-Za-z]+$");
if (v1.IsMatch(singleLine))`
{
...
...
}
Using #"^[A-Za-z]+\s[=]\s[A-Za-z]+$" this expression 2nd string is matched but not first and when used this #"^[A-Za-z]+\s[=]\s\d{0,3}$" then only matched first one.
And i also want to check for radius = 'val01'

Basing on your effort, it looks as if you were trying to come up with
^[A-Za-z]+\s=\s(?:'[A-Za-z0-9]+'|\d{1,3})$
See the regex demo. Details:
^ - start of string
[A-Za-z]+ - one or more ASCII letters
\s=\s - a = char enclosed with single whitespace chars
(?:'[A-Za-z0-9]+'|\d{1,3}) - a non-capturing group matching either
'[A-Za-z0-9]+' - ', then one or more ASCII letters or digits and then a '
| - or
\d{1,3} - one, two or three digits
$ - end of string (actually, \z is safer when it comes to validating as there can be no final trailing newline after \z, and there can be such a newline after $, but it also depends on how you obtain the input).

If the pattern you tried ^[A-Za-z]+\s[=]\s[A-Za-z]+$ matches the second string radius = 'value', that means that 'value' consists of only chars A-Za-z.
In that case, you could either add matching digits to the second character class:
^[A-Za-z]+\s=\s[A-Za-z0-9]+$
If you either want to match 1-3 digits or at least a single char A-Za-z followed by optional digits:
^[A-Za-z]+\s=\s(?:[0-9]{1,3}|[A-Za-z]+[0-9]*)$
The pattern matches:
^ Start of string
[A-Za-z]+\s=\s Match the first part with chars A-Za-z and the = sign (Note that = does not have to be between square brackets)
(?: Non capture group
[0-9]{1,3} Match 1-3 digits (You can use \d{0,3} but that will also match an emtpy string due to the 0)
| Or
[A-Za-z]+[0-9]* Match 1+ chars A-Za-z followed by optional digits
) Close non capture group
$ End of string
Regex demo

Formatting a Phone number [duplicate]

This question already has answers here:
Replace non-numeric with empty string
(9 answers)
Closed 8 years ago.
How can I format a phone number from (###)###-#### to ##########? Is there best way to do that? I can use String.Substring to get each block of numbers and then concatenate them. But, Is there any other sophisticated way of doing it?

How about a simple Regex replace?
string formatted = Regex.Replace(phoneNumberString, "[^0-9]", "");
This is essentially just a white list for numbers only. See this fiddle: http://dotnetfiddle.net/ssdWSd
Input: (123) 456-7890
Output: 1234567890

I'd do it using LINQ:
var result = new String(phoneString.Where(x => Char.IsDigit(x)).ToArray());
While regex also works, this doesn't require any special set up.

A simple way would be:
myString = myString.Replace("(", "");
myString = myString.Replace(")", "");
myString = myString.Replace("-", "");
Replace each character with an empty string.

Try this:
resultString = Regex.Replace(subjectString, #"^\((\d+)\)(\d+)-(\d+)$", "$1$2$3");
REGEX EXPLANATION
^\((\d+)\)(\d+)-(\d+)$
Assert position at the beginning of the string «^»
Match the character “(” literally «\(»
Match the regex below and capture its match into backreference number 1 «(\d+)»
Match a single character that is a “digit” (0–9 in any Unicode script) «\d+»
Between one and unlimited times, as many times as possible, giving back as needed (greedy) «+»
Match the character “)” literally «\)»
Match the regex below and capture its match into backreference number 2 «(\d+)»
Match a single character that is a “digit” (0–9 in any Unicode script) «\d+»
Between one and unlimited times, as many times as possible, giving back as needed (greedy) «+»
Match the character “-” literally «-»
Match the regex below and capture its match into backreference number 3 «(\d+)»
Match a single character that is a “digit” (0–9 in any Unicode script) «\d+»
Between one and unlimited times, as many times as possible, giving back as needed (greedy) «+»
Assert position at the end of the string, or before the line break at the end of the string, if any (line feed) «$»
$1$2$3
Insert the text that was last matched by capturing group number 1 «$1»
Insert the text that was last matched by capturing group number 2 «$2»
Insert the text that was last matched by capturing group number 3 «$3»

.NET Regex - Specific String containing a changing number

I am new to working with Regexs in C# .NET. Say I have a string as follows...
"Working on log #4"
And within this string we can expect to see the number (4) vary. How can I use a Regex to extract only that number from the string.
I want to make sure that the string matches the first part:
"Working on log #"
And then exctract the integer from it.
Also - I know that I could do this using string.Split(), or .Substring, etc. I just wanted to know how I might use regex's to do this.
Thanks!

"Working on log #(\d+)"
The () create a match group, so you will be able to extract that section.
The \d matches any digit.
The + says "look at the previous token, match it one or more times" so it will make it match one or more digits.
So overall you're capturing a group containing one or more digits, where that group comes after "Working on log #"

RegEx rgx = new RegEx("Working on log #[0-9]"); is the pattern you want to use. The first part is a string literal, [0-9] says that character can be any value 0 through 9. If you allow multiple digits then change it to [0-9]{x} where x is the number of repetitions or [0-9]+ as a + after any character means 1 or more of that character is allowed.
You could also just do string.StartsWith("Working on log #") then split on # and use int.TryParse() with the second value to confirm it is in fact a valid integer.

Try this: ^(?<=Working on log #)\d+$. This only captures the number. No need for a capture group. Remove ^ and $ if this is within a larger string.
^ - start of string
(?<=) - positive lookbehind - ensures what is between = and ) is found before
\d+ - at least one digit
$ - end of string

A capturing group is the solution:
"Working on log #(?<Number>[0-9]+)"
Then you can access the matched groups using the Match.Groups property.

Make Regex stop looking at \n

I have the following string:
"\t Product: ces DEVICE TYPE \nSometext" //between ":" and "ces" are 9 white spaces
I need to parse the part "DEVICE TYPE". I'm trying to do this with Regex. I use this expression, which works.
((?<=\bProduct:)(\W+\w+){3}\b)
this expression returns:
" ces DEVICE TYPE"
The problem is here: Some devices have a string like this:
"\t Product: ces DEVICETYPE \nSometext"
If I use the same expression to parse the device type I get this as result:
" ces DEVICETYPE \nSometext"
How do I get my regex to stop when a \n is found?

Perhaps this?
(?<=ces)[^\\n]+
If all you want is what's after ces and before \n that is..

In .NET you can use RegexOptions.Multiline. This changes the behaviour of ^ and $.
Rather than meaning the start and end of your string, they now mean start and end of any line within your string.
Regex r = new Regex(#"(?<=\bProduct:).+$", RegexOptions.Multiline);

You could use:
(?m)((?<=\bProduct:).+)
Explanation:
(?m)((?<=\bProduct:).+)
Match the remainder of the regex with the options: ^ and $ match at line breaks (m) «(?m)»
Match the regular expression below and capture its match into backreference number 1 «((?<=\bProduct:).+)»
Assert that the regex below can be matched, with the match ending at this position (positive lookbehind) «(?<=\bProduct:)»
Assert position at a word boundary «\b»
Match the characters “Product:” literally «Product:»
Match any single character that is not a line break character «.+»
Between one and unlimited times, as many times as possible, giving back as needed (greedy) «+»
or
((?<=\bProduct:)[^\r\n]+)
Explanation
((?<=\bProduct:)[^\r\n]+)
Match the regular expression below and capture its match into backreference number 1 «((?<=\bProduct:)[^\r\n]+)»
Assert that the regex below can be matched, with the match ending at this position (positive lookbehind) «(?<=\bProduct:)»
Assert position at a word boundary «\b»
Match the characters “Product:” literally «Product:»
Match a single character NOT present in the list below «[^\r\n]+»
Between one and unlimited times, as many times as possible, giving back as needed (greedy) «+»
A carriage return character «\r»
A line feed character «\n»

C# regex to replace a delimiter by another one

I'm working on pl/sql code where i want to replace ';' which is commented with '~'.
e.g.
If i have a code as:
--comment 1 with;
select id from t_id;
--comment 2 with ;
select name from t_id;
/*comment 3
with ;*/
Then i want my result text as:
--comment 1 with~
select id from t_id;
--comment 2 with ~
select name from t_id;
/*comment 3
with ~*/
Can it be done using regex in C#?

Regular expression:
((?:--|/\*)[^~]*)~(\*/)?
C# code to use it:
string code = "all that text of yours";
Regex regex = new Regex(#"((?:--|/\*)[^~]*)~(\*/)?", RegexOptions.Multiline);
result = regex.Replace(code, "$1;$2");
Not tested with C#, but the regular expression and the replacement works in RegexBuddy with your text =)
Note: I am not a very brilliant regular expression writer, so it could probably have been written better. But it works. And handles both your cases with one-liner-comments starting with -- and also the multiline ones with /* */
Edit: Read your comment to the other answer, so removed the ^ anchor, so that it takes care of comments not starting on a new line as well.
Edit 2: Figured it could be simplified a bit. Also found it works fine without the ending $ anchor as well.
Explanation:
// ((?:--|/\*)[^~]*)~(\*/)?
//
// Options: ^ and $ match at line breaks
//
// Match the regular expression below and capture its match into backreference number 1 «((?:--|/\*)[^~]*)»
// Match the regular expression below «(?:--|/\*)»
// Match either the regular expression below (attempting the next alternative only if this one fails) «--»
// Match the characters “--” literally «--»
// Or match regular expression number 2 below (the entire group fails if this one fails to match) «/\*»
// Match the character “/” literally «/»
// Match the character “*” literally «\*»
// Match any character that is NOT a “~” «[^~]*»
// Between zero and unlimited times, as many times as possible, giving back as needed (greedy) «*»
// Match the character “~” literally «~»
// Match the regular expression below and capture its match into backreference number 2 «(\*/)?»
// Between zero and one times, as many times as possible, giving back as needed (greedy) «?»
// Match the character “*” literally «\*»
// Match the character “/” literally «/»

A regex is not really needed - you can iterate on lines, locate the lines starting with "--" and replace ";" with "~" on them.
String.StartsWith("--") - Determines whether the beginning of an instance of String matches a specified string.
String.Replace(";", "~") - Returns a new string in which all occurrences of a specified Unicode character or String in this instance are replaced with another specified Unicode character or String.