Remove keywords and operators from string expression

Question

I need you help I have one string like

a1 + b1 + ( v1 + g1 ) * 10

I need to retrieve only a1,b1,v1,g1 any idea

Possible duplicate of [Remove characters from C# string](http://stackoverflow.com/questions/7411438/remove-characters-from-c-sharp-string) — René Vogt, May 25 '16 at 11:09
What have you already tried? Or should we do all the work that was assigned to you? — MakePeaceGreatAgain, May 25 '16 at 11:21

score 1 · Accepted Answer · answered May 25 '16 at 11:11

1

I would use RegEx to filter the desired output. Assuming that your result always starts with a small letter and ends with a digit [a-z][0-9]

string input = "a1 + b1 + ( v1 + g1 ) * 10";
List<string> Result = Regex.Matches(input, @"[a-z][0-9]")
                            .Cast<Match>()
                            .Select(x => x.Value)
                            .ToList();

answered May 25 '16 at 11:11

fubo

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no dear its not working and also it is giving error on does not contain definition for cast – Mayur Gujrathi May 25 '16 at 11:28
1

add `using System.Text.RegularExpressions;` and `using System.Linq;` – fubo May 25 '16 at 11:29
what if my string will be like this sss + aaa + AAA + ddd + 10 - www ..this time i would like to retrieve complete string like aaa,AAA – Mayur Gujrathi May 25 '16 at 11:48
then reaplce `[a-z][0-9]` with `[a-zA-Z]{3}` for _3 letters_ – fubo May 25 '16 at 11:53

score 0 · Answer 2 · answered May 25 '16 at 11:47

0

I'd go after it using a recursive descent parser. It may seem as an overkill to start with but it will work for all sorts of expressions.

Here's a good introduction to the theory.

answered May 25 '16 at 11:47

Tomaz Stih

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Remove keywords and operators from string expression

2 Answers2