c# how to find negative values in string and convert it?-CodePudding

i get strings like this:

[(0  -0,01)*(0,724-0)  (-0,01  -17,982)*(0,725-0,724)  (-17,982  -17,983)*(1,324-0,725)  (-17,983  -30,587)*(1,323-1,324)  (-30,587  -30,587)*(-0,004-1,323)  (-30,587  0)*(0--0,004)]*0,5

i have to convert it in a way that --xx,xx or -xx,xx will be set in brackets -(-xx,xx) or (-xx,xx)

like this:

[(0  (-0,01))*(0,724-0)  (-0,01  (-17,982))*(0,725-0,724)  (-17,982  (-17,983))*(1,324-0,725)  (-17,983  (-30,587))*(1,323-1,324)  (-30,587  (-30,587))*(-0,004-1,323)  (-30,587  0)*(0-(-0,004))]*0,5

but i have no idea to do this.

CodePudding user response：

You can try regular expressions, e.g.

  using System.Text.RegularExpressions;

  ... 

  string source =
    "[(0  -0,01)*(0,724-0)  (-0,01  -17,982)*(0,725-0,724)  (-17,982  -17,983)*(1,324-0,725)  (-17,983  -30,587)*(1,323-1,324)  (-30,587  -30,587)*(-0,004-1,323)  (-30,587  0)*(0--0,004)]*0,5";

  string result = Regex.Replace(source, @"(?<=[ -])-[0-9] (\,[0-9] )?", "($&)");

  Console.Write(result);

Outcome:

  [(0  (-0,01))*(0,724-0)  (-0,01  (-17,982))*(0,725-0,724)  (-17,982  (-17,983))*(1,324-0,725)  (-17,983  (-30,587))*(1,323-1,324)  (-30,587  (-30,587))*(-0,004-1,323)  (-30,587  0)*(0-(-0,004))]*0,5

Here we look for (?<=[ -])-[0-9] (\,[0-9] )? pattern:

  (?<=[ -]) - look ahead for   or -
          - - "-" 
     [0-9]  - one or more digit in 0..9 range - integer part
(\,[0-9] )? - optional fractional part: comma then one or more digit in 0..9 range

Each match we wrap into (..) - "($&)"