Expression calculation in c#

Devendra Kumar

5y965Learn iOS Programming

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

8 Replies

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Laxmidhar Sahoo5y ago
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
0
Devendra Kumar5y ago
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
+1
Sachin Singh5y ago
@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.
+2
Devendra Kumar5y ago
@Sachin

I tried the way you suggested but the result is wrong

The output should be 105

/100 doesn't work
-3
Rijwan Ansari5y ago
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
0
Sachin Singh5y ago
proceed as
var expression = "2+5%";
if(expression.Contains("%"))
{
expression=expression.Replace("%", "/100")
}
var result = new DataTable().Compute(expression,"")+"";
Note :- using System.Data
+2
Devendra Kumar5y ago
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 %
+1
Sachin Singh5y ago
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
0