c# - How to parse the following string -

i trying generate formula this, sample,

a + b + c > d - 

now, a, b, c, d, etc column names of sheet (like excel sheet) accessing in memory.

i need generate rule, above a + b + c > d - a decide kind of values user can add in cell.

currently how have begun:

string tovalidate = "a + b + c > d + e - a"; string lhs = "", rhs = ""; string[] comparisonoperators = new string[] { "=", ">", "<", "<>", "!=" }; char[] arithmeticoperators = { '+', '-', '/', '*' }; tovalidate = tovalidate.replace(@" ", "");   (int = 0; < comparisonoperators.length; i++) {     if (tovalidate.contains(comparisonoperators[i]))     {         operatorindex = tovalidate.indexof(comparisonoperators[i]);         break;     } } lhs = tovalidate.substring(0, operatorindex); rhs = tovalidate.substring(operatorindex + 1); string[] columnlhslist = lhs.split(arithmeticoperators); string[] columnrhslist = rhs.split(arithmeticoperators); 

however though have strings lhs , rhs , operator > in above code, not able understand how can apply formula on sheet itself. need know column has operator associated.

since have individual column names, not operator before them, e.g,

+ before a - before a in case.

how parse above please help.

it is, however, fun question if want make simple formula parsers yourself.

i advice check out article, since written , understandable because of it.

shunting-yard algorithm