Regular expression replace in C

Question

I m fairly new to using regular expressions  and  based on a few tutorials I ve read  I m unable to get this step in my Regex Replace formatted properly   Here s the scenario I m working on    When I pull my data from the listbox  I want to format it into a CSV like format  and then save the file  Is using the Replace option an ideal solution for this scenario   Before the regular expression formatting example   FirstName LastName Salary    Position ------------------------------------- John      Smith     100 000 00  M   Proposed format after regular expression replace  John Smith 100000 M   Current formatting status output   John Smith 100000 M    Note - is there a way I can replace the first comma with a whitespace   Snippet of my code  using var fs   new FileStream filepath  FileMode OpenOrCreate  FileAccess Write         using var sw   new StreamWriter fs                 foreach  string stw in listBox1 Items                        StringBuilder sb   new StringBuilder                sb AppendLine stw                  Piecing the list back to the original format             sb trim   Regex Replace stw                            sb trim   Regex Replace sb trim        0-9                      sb trim   Regex Replace sb trim     s                     sw WriteLine sb trim

User · Answer

Add the following 2 lines  var regex   new Regex Regex Escape        sb trim   regex Replace sb trim       1     If sb trim  John Smith 100000 M the above code will return  John Smith 100000 M

User · Answer

Try this    sb trim   Regex Replace stw      D   s      d       d  s           m   gt  string Format            0   1   2            m Groups 1  Value          m Groups 2  Value Replace      string Empty           m Groups 3  Value      This is about as clean an answer as you ll get  at least with regexes      D    First capture group   One or more non-digit characters   s     One or more spacing characters  then a literal dollar sign         d      Second capture group   One or more digits and or commas     d   Decimal point  then at least one digit   s   One or more spacing characters       Third capture group   Any non-line-breaking character    The second capture group additionally needs to have its commas stripped   You could do this with another regex  but it s really unnecessary and bad for performance   This is why we need to use a lambda expression and string format to piece together the replacement   If it weren t for that  we could just use this as the replacement  in place of the lambda expression     1  2  3

User · Answer

You can do it this with two replace s    let stw be  John Smith  100 000 00 M   sb trim   Regex Replace stw     s     s     w              sb trim becomes  John Smith 100 000 00 M   sb trim   Regex Replace sb trim       lt   d      d     0                sb trim becomes  John Smith 100000 M   sw WriteLine sb trim

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