Question

Possible Duplicate:
calculate result from a string expression dynamically

I have the following formula saved in XML as element value- “d1*2”.
After I extract this from the XML as a string how can I assign a value to the “d1”
and calculate the formula result?

Answer 1

This looks like it’s exactly what you’re looking for:

https://github.com/Giorgi/Math-Expression-Evaluator

The author’s done a really good and thorough write-up of the usage and design here:

http://www.aboutmycode.com/net-framework/building-expression-evaluator-with-expression-trees-in-csharp-table-of-contents/

Usage goes like this (copied from the examples):

var a = 6;
var b = 4.32m;
var c = 24.15m;
var result = engine.Evaluate("(((9-a/2)*2-b)/2-a-1)/(2+c/(2+4))", new { a, b, c});

Google is, of course, your friend… there are a bunch of others out there, but this by far looks like the most mature project.

EDIT: This other SO answer also mentions NCalc, which is similar: https://stackoverflow.com/a/10063089/381587