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Posted 14 May 2012

# Math Parser .NET C#

, 28 Feb 2014
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This is light, fast and simple to understand mathematical parser designed in one class, which receives as input a mathematical expression (System.String) and returns the output value (System.Double)

## Introduction

This is light, fast and simple to understand mathematical parser designed in one class, which receives as input a mathematical expression (System.String) and returns the output value (System.Double). For example, if your input string is "√(625)+25*(3/3)" then parser returns double value — 50.

## Background

The idea was to create a string calculator for educational goals.

## How it work

For more please look at the code, I tried to explain the work of the parser in the comments and how it can be changed and extended.

Convert to RPN:

* Input operators are replaced by the corresponding token (its necessary to distinguish unary from binary).

## Using the code

Example:

```public static void Main()
{
MathParser parser = new MathParser();
string s1 = "pi+5*5+5*3-5*5-5*3+1E1";
string s2 = "sin(cos(tg(sh(ch(th(100))))))";

Console.WriteLine(d1); // 13.141592...
Console.WriteLine(d2); // 0.0174524023974442
}
```

## Features

Ariphmetical operators :

• () — parentheses;
• + —  plus (a + b);
• - — minus (a - b);
• * — multiplycation symbol (a * b);
• / — divide symbol (a / b);
• ^ — degree symbol (a ^ b).

Functions :

Trigonometric functions:

• sin(x);
• cos(x);
• tg(x);
• ctg(x).

Hyperbolic functions:

• sh(x);
• ch(x);
• th(x).

Other functions:
• √(a), sqrt(a) — square root of a number;
• exp(x)  — exponential function (or just use e^x);
• (a)log(b) — logarithm;
• ln(x) — natural logarithm;
• abs(x) — absolute value.

Constants:

• pi — 3.14159265...;
• e — 2.71828183....

Arguments of the trigonometric functions can be expressed as radians (true) or degrees (false) by sending appropriate bool value to parse method. Example (as radians):

`parser.Parse("sin(90)", true);`

Work with any char decimal separator in real number (regional settings).

New operators, functions and constants can be easily added to the code.

This parser is simple (special designed in single class), convenient for the further implementation, expansion and modification.

## Points of Interest

I better understand how parsers work and learned about the reverse-polish notation.

## History

• 2012/05/09: released the source code (1_0);
• 2012/06/07: optimized parser (1_2);
• 2014/02/28: rewritten version (1_4).

## Share

 Kazakstan
His name is Yerzhan Kalzhani. He's a pragmatic software developer who loves tasks that are interesting and challenging. His motto in software developing: "Quality, Performance and Agile".

He prefers systematic approach when solving a problem, so he thinks that every good developer, first of all, should be able to manage the complexity of a software system and produce the well-structured solution for a poorly defined problem.

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 Re: My vote of 4 Andreas Gieriet27-Jan-13 9:19 Andreas Gieriet 27-Jan-13 9:19
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 Code Clifford Nelson24-Aug-12 8:07 Clifford Nelson 24-Aug-12 8:07
 Re: Code kirnbas24-Aug-12 8:46 kirnbas 24-Aug-12 8:46
 Sym Warren Harding16-Aug-12 21:32 Warren Harding 16-Aug-12 21:32
 Re: Sym kirnbas24-Aug-12 7:19 kirnbas 24-Aug-12 7:19
 Broken Image links Marcus Kramer7-Jun-12 5:53 Marcus Kramer 7-Jun-12 5:53
 Could you update your image links, please? They are not working. (At least on my box) I wasn't, now I am, then I won't be anymore.
 Re: Broken Image links kirnbas7-Jun-12 6:32 kirnbas 7-Jun-12 6:32
 Please show and explain the code PIEBALDconsult14-May-12 14:51 PIEBALDconsult 14-May-12 14:51
 Re: Please show and explain the code kirnbas15-May-12 3:22 kirnbas 15-May-12 3:22
 Re: Please show and explain the code PIEBALDconsult15-May-12 8:03 PIEBALDconsult 15-May-12 8:03
 Quite complicated expression evaluator... Andreas Gieriet14-May-12 13:18 Andreas Gieriet 14-May-12 13:18
 You might want to elaborate on some of the inner workings, etc. ednrg14-May-12 9:07 ednrg 14-May-12 9:07
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