Expression calculation in c#

Question

I want to implement an arithmatic operation in an textbox like when user type it eg textbox1.Text= "2+5%"; // not to do operation of modulo, user want to calculate tax output required = 2.1 user can type any expression and i want to calculate the result (like 2+(3*5)/2-8)) how can I achieve this Thanks Devendra

Sachin Singh · Answer

@Devendra 100+ 5% is always 100.05 unless it is not a simple interest concept , bro use some mathematics as well. what you want is principal+ Principal*5% , accordingly adjust your percentage. and remember % always varies wrt principal 100% means wrt principal , if principal is 100 then you will get 105 but if principal is 20 rs then with 5% you will get just 21 rs and not 26 rs. So the problem is in your algorithm and not in the method that is proposed to you. How you define percentage is completely up to you depending on which type of interest are you calculating.

Sachin Singh · Answer

proceed as var expression = "2+5%" ; if (expression.Contains( "%" )) { expression=expression.Replace( "%" , "/100" ) } var result = new DataTable().Compute(expression, "" )+ "" ; Note :- using System.Data

Devendra Kumar · Answer

I am not implementing any concept of calculating SI or any. Customer wants to calculate the expression given in a textbox and get the result just like calculator works I tried some infix to postfix but I couldn't able to implement it, its confusing. It would be really appreciated if you can help me out Thanks in advance Devendra

Rijwan Ansari · Answer

You can use DataTable.Compute(String, String) for simple expression like var outValue = new DataTable().Compute( "2-3/4*12" , null ); More details: https://docs.microsoft.com/en-us/dotnet/api/system.data.datatable.compute Alternatively, you can build your own parser and the logic to compute the result

Devendra Kumar · Answer

Thanks sachin for your answer but I couldn't able to parse % (as for calculating tax). Can you please help me to get the sample code because I am not able to parse the logic for %

Sachin Singh · Answer

create an expression tree for this https://codereview.stackexchange.com/questions/93997/expression-calculator or @Amit Gupta sir has witten an article on it that might help https://www.c-sharpcorner.com/blogs/calculator-calculation-with-single-line-of-code-in-c-sharp

Laxmidhar Sahoo · Answer

hi First, convert your express to simple brackets with arithmetic operations by removing special charectore ike % ,^ Then use logic for calculate the expression Thanks and regards

Devendra Kumar · Answer

@Sachin I tried the way you suggested but the result is wrong The output should be 105 /100 doesn't work