Awesome Open Source
Awesome Open Source

ExpressionEvaluator Icon


A Simple Math and Pseudo C# Expression Evaluator in One C# File.

And from version 1.2.0 can execute small C# like scripts

It is largely based on and inspired by the following resources this post on stackoverflow, NCalc, C# Operators and C# Statement Keywords


Branch Status
master Build Status
dev Dev Status
nuget NuGet Status


And with ScriptEvaluate method

  • Small C# like script evaluation (Multi expressions separated by ; )
  • Some conditional and loop blocks keywords (if, while, for, foreach ...)
  • Multi-line (multi expression) Lambda expressions. (Can be use as method See #72 Declare methods in scripts and the doc)


And more is coming

Similar projects


  • NCalc
  • Jint Support scripting but with Javascript
  • NLua use Lua language in C#
  • DynamicExpresso
  • Flee
  • CS-Script Best alternative (I use it some times) -> Real C# scripts better than ExpressionEvaluator (But everything is compiled. Read the doc. Execution is faster but compilation can make it very slow. And if not done the right way, it can lead to memory leaks)
  • Roslyn The Microsoft official solution (For scripting see)
  • MathParser expression tree compiler and interpreter for math expressions. Heavily inspired by Roslyn.


I would say every C# evaluation libraries have drawbacks and benefits, ExpressionEvaluator is not an exception so choose wisely (Read docs and licences).

The biggest difference of ExpressionEvaluator is that everything is evaluated on the fly, nothing is compiled or transpile nor in CLR/JIT/IL nor in lambda expressions nor in javascript or other languages stuffs. So it can be slower in some cases (sometimes not) but it also avoid a lot of memory leaks. It already allow to evaluate some small scripts. If you don't want an another .dll file in your project, you only need to copy one C# file in your project. And it's MIT licence


Expression Evaluator is free and will always be.
But if you want to say thanks for this lib with a donation or small sponsoring here you can :

Thank you anyway for using ExpressionEvaluator

Get A Weekly Email With Trending Projects For These Topics
No Spam. Unsubscribe easily at any time.
C Sharp (278,209
Parser (4,869
Script (3,900
Math (3,607
Scripting (801
Reflection (646
Evaluation (376
Expression (277
Calculations (232
Fluid (162
Expression Evaluator (135
Related Projects