https://github.com/matheval/expression-evaluator-c-sharp
Matheval is a mathematical expressions evaluator library written in C#. Allows to evaluate mathematical, boolean, string and datetime expressions
https://github.com/matheval/expression-evaluator-c-sharp
calculator eval evaluator expression-evaluator expresssion fomular math mathematical-expressions-evaluator mathematics
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Matheval is a mathematical expressions evaluator library written in C#. Allows to evaluate mathematical, boolean, string and datetime expressions
- Host: GitHub
- URL: https://github.com/matheval/expression-evaluator-c-sharp
- Owner: matheval
- License: mit
- Created: 2021-07-27T07:48:38.000Z (over 4 years ago)
- Default Branch: main
- Last Pushed: 2024-08-26T15:19:10.000Z (over 1 year ago)
- Last Synced: 2025-08-24T09:28:04.527Z (6 months ago)
- Topics: calculator, eval, evaluator, expression-evaluator, expresssion, fomular, math, mathematical-expressions-evaluator, mathematics
- Language: C#
- Homepage: https://matheval.org/
- Size: 96.7 KB
- Stars: 127
- Watchers: 8
- Forks: 34
- Open Issues: 22
-
Metadata Files:
- Readme: README.md
- Contributing: CONTRIBUTING.md
- License: LICENSE
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README
# About MathEval
[](https://www.nuget.org/packages/org.matheval/)
Matheval is a mathematical expressions evaluator library written in C#. Allows to evaluate mathematical, boolean, string and datetime expressions
Code is written in pure C#, run on the fly. We don't use any third party libraries or packages
If you get any bugs please let me know by creating a new issue.
**Many thanks to our contributors:**
[Thanhrin](https://github.com/ThanhRin) (from Da Nang, VietNam)
[Eduardo Salinas](https://github.com/butulia) (from Huesca, Spain)
# Installation
Using Package Manager
```bash
PM> Install-Package org.matheval -Version 1.0.0.3
```
# Supported operators, contants, functions
## Supported Operators
Operator
Description
+
Additive operator / Unary plus / Concatenate string / Datetime addition
&
Concatenate string
–
Subtraction operator / Unary minus / Datetime subtraction
*
Multiplication operator, can be omitted in front of an open bracket
/
Division operator
%
Remainder operator (Modulo)
^
Power operator
## Supported conditional statements
Conditional statement
Description
IF(logical_condition, value_if_true, value_if_false)
Example:
`IF(2>1,"Pass","Fail")`
SWITCH(expression, val1,result1, [val2,result2], …, [default])
Example:
`SWITCH(3+2,5,"Apple",7,"Mango",3,"Good","N/A")`
## Supported logical and math functions
Function*
Description
AND(logical1, [logical2], …)
Determine if all conditions are TRUE
OR(logical1, [logical2], …)
Determine if any conditions in a test are TRUE
NOT(_logical_)
To confirm one value is not equal to another
XOR(logical1, [logical2], …)
Exclusive OR function
SUM(number1, [number2],…)
Return sum of numbers supplied
AVERAGE(number1, [number2],…)
Return average of numbers supplied
MIN(number1, [number2],…)
Return the smallest value from the numbers supplied
MAX(number1, [number2],…)
Return the biggest value from the numbers supplied
MOD(number, divisor)
Get remainder of two given numbers after division operator.
ROUND(number, num_digits)
Returns the rounded approximation of given number using half-even rounding mode
( you can change to another rounding mode)
FLOOR(number, significance)
Rounds a given number towards zero to the nearest multiple of a specified significance
`CEILING`(number, significance)
Rounds a given number away from zero, to the nearest multiple of a given number
POWER(number, power)
Returns the result of a number raised to a given power
RAND()
Produces a random number between 0 and 1
SIN(number)
Returns the trigonometric sine of the angle given in radians
SINH(number)
Returns the hyperbolic sine of a number
ASIN(number)
Returns the arc sine of an angle, in the range of -pi/2 through pi/2
COS(number)
Returns the trigonometric cos of the angle given in radians
COSH(number)
Returns the hyperbolic cos of a number
ACOS(number)
Returns the arc cosine of an angle, in the range of 0.0 through pi
TAN(number)
Returns the tangent of the angle given in radians
TANH(number)
Returns the hyperbolic tangent of a number
ATAN(number)
Returns the arc tangent of an angle given in radians
ATAN2(x_number, y_number)
Returns the arctangent from x- and y-coordinates
COT(number)
Returns the cotangent of an angle given in radians.
COTH(number)
Returns the hyperbolic cotangent of a number
SQRT(number)
Returns the correctly rounded positive square root of given number
LN(number)
Returns the natural logarithm (base _e_) of given number
LOG10(number)
Returns the logarithm (base 10) of given number
EXP(number)
Returns e raised to the power of given number
ABS(number)
Returns the absolute value of given number
FACT(number)
Returns the factorial of a given number
SEC(number)
Returns the secant of an angle given in radians
CSC(number)
Returns the cosecant of an angle given in radians
PI()
Return value of Pi
RADIANS(degrees)
Convert degrees to radians
DEGREES(radians)
Convert radians to degrees
INT(number)
Returns the Integer value of given number
## Supported Constants
Constant
Description
e
The value of _e_
PI
The value of _PI_
TRUE
The boolean true value
FALSE
The boolean false value
NULL
The null value
## Supported text functions
Function
Description
LEFT(text, num_chars)
Extracts a given number of characters from the left side of a supplied text string
RIGHT(text, num_chars)
Extracts a given number of characters from the right side of a supplied text string
MID(text, start_num, num_chars)
Extracts a given number of characters from the middle of a supplied text string
REVERSE(text)
Reverse a string
ISNUMBER(text)
Check if a value is a number
LOWER(text)
Converts all letters in the specified string to lowercase
UPPER(text)
Converts all letters in the specified string to uppercase
PROPER(text)
Capitalizes words given text string
TRIM(text)
Removes extra spaces from text
LEN(text)
Returns the length of a string/ text
TEXT(value, [format_text])
Convert a numeric value into a text string. You can use the TEXT function to embed formatted numbers inside text
Example:
`
TEXT(123) -> 123
`TEXT(123) -> 123`
TEXT(DATEVALUE("2021-01-23"),"dd-MM-yyyy") -> 23-01-2021
`TEXT(DATEVALUE("2021-01-23"),"dd-MM-yyyy") -> 23-01-2021`
TEXT(2.61,"hh:mm") -> 14:38
`TEXT(2.61,"hh:mm") -> 14:38`
TEXT(2.61,"[hh]") -> 62
`TEXT(2.61,"[hh]") -> 62`
TEXT(2.61,"hh-mm-ss") -> 14-38-24
`TEXT(2.61,"hh-mm-ss") -> 14-38-24`
TEXT(DATEVALUE("2021-01-03")-DATEVALUE("2021-01-01"),"[h]") -> 48
`TEXT(DATEVALUE("2021-01-03")-DATEVALUE("2021-01-01"),"[h]") -> 48`
TEXT(TIME(12,00,00)-TIME(10,30,10),"hh hours and mm minutes and ss seconds") -> "01 hours and 29 minutes and 50 seconds"
`TEXT(TIME(12,00,00)-TIME(10,30,10),"hh hours and mm minutes and ss seconds") -> "01 hours and 29 minutes and 50 seconds"``
REPLACE(old_text, start_num, num_chars, new_text)
Replaces characters specified by location in a given text string with another text string
SUBSTITUTE(text, old_text, new_text)
Replaces a set of characters with another
FIND(find_text, within_text, [start_num])
Returns the location of a substring in a string (case sensitive)
SEARCH(find_text, within_text, [start_num])
Returns the location of a substring in a string (case insensitive)
CONCAT(text1, text2, text3,…)
Combines the text from multiple strings
ISBLANK(text)
Returns TRUE when a given string is null or empty, otherwise return FALSE
REPT(text, repeat_time)
Repeats characters a given number of times
CHAR(char_code)
Return character from ascii code
CODE(char)
Returns a ascii code of a character
VALUE(text)
Convert numbers stored as text to numbers
# Usage examples
## Basic evaluator
```cs
using System;
using org.matheval;
public class Program
{
public static void Main()
{
Expression expression = new Expression("(a + b) / 2 ");
expression.Bind("a", 3);
expression.Bind("b",5);
Object value = expression.Eval();
Console.WriteLine("Result: "+value); //Result: 4
}
}
```
## Conditional statements
IF/ELSE
```cs
using System;
using org.matheval;
public class Program
{
public static void Main()
{
Expression expression = new Expression("IF(time>8, (HOUR_SALARY*8) + (HOUR_SALARY*1.25*(time-8)), HOUR_SALARY*time)");
//bind variable
expression.Bind("HOUR_SALARY", 10);
expression.Bind("time", 9);
//eval
Decimal salary = expression.Eval();
Console.WriteLine(salary); //return 92.5
}
}
```
SWITCH/CASE
```cs
Expression expr = new Expression("SWITCH(name,1,'apple',2,'mango',3,'banana','N/A')");
//Bind variable
expr.Bind("name", 2);
//eval
String value = expr.Eval(); //return "mango"
```
## Validate expression
```cs
Expression expression = new Expression("SUM(1,2,3) + true");
List errors = expression.GetError();
if(errors.Count > 0)
{
foreach(String error in errors)
{
Console.WriteLine(error);
}
}
```
## Get variables that appear in the expression
```cs
Expression expression = new Expression("sin(pi/2+x)-cos(x) = a");
//validate expression
List errors = expression.GetError();
if (errors.Count == 0)
{
// get variables
List variables = expression.getVariables();
foreach (String variable in variables)
{
Console.WriteLine(variable); // will print x, a
}
}
```
## Disable functions
```cs
Expression expression = new Expression();
expression.DisableFunction("SIN");
expression.DisableFunction("COS");
```
```cs
Expression expression = new Expression();
expression.DisableFunction(new string[] { "SIN", "COS" });
```
# Work with number expression
Scale and rounding mode
Use setScale() method to set number of digits to the right of the decimal point. Use setRoundingMode() method to set rounding mode. You can choose 1 of the following options:
MidpointRounding.AwayFromZero
MidpointRounding.ToEven
MidpointRounding.ToZero
```cs
Expression expression = new Expression("pi/2");
expression.SetScale(3);
expression.SetRoundingMode(MidpointRounding.ToEven);
Decimal value = expression.Eval();//return 1.571
```
## Min, max, sum, avg
```cs
Expression expr = new Expression("MIN(a,b,c)");
expr.Bind("a", 2);
expr.Bind("b", 3);
expr.Bind("c", 16);
int value = expr.Eval(); // return 2
```
```cs
Expression expr = new Expression("MAX(a)");
expr.Bind("a", new List { 10m, 9.6m, 135, 724.2m, 6m, -4m });
Decimal value = expr.Eval(); // return 724.2
```
```cs
Expression expr = new Expression("SUM(a,b,c)");
expr.Bind("a", 2d);
expr.Bind("b", 3d);
expr.Bind("c", 16d);
Double sum = expr.Eval(); // return 21
expr.SetFomular("AVERAGE(a,b,c)");
Double avg = expr.Eval(); // return 7
```
```cs
Expression expr = new Expression("SUM(a)");
expr.Bind("a", new List { 2m, 3m, 16m });
Decimal sum = expr.Eval(); // return 21
expr.SetFomular("AVERAGE(a)");
Decimal avg = expr.Eval(); // return 7
```
```cs
using System;
using org.matheval;
public class Program
{
public static void Main()
{
Expression expr = new Expression("MIN(2,3,16)");
int min = expr.Eval();
Console.WriteLine(min);// return 2 (min)
expr.SetFomular("Max(2,3,16)");
int max = expr.Eval();
Console.WriteLine(max);// return 16 (max)
expr.SetFomular("Sum(2,3,16)");
decimal sum = expr.Eval();
Console.WriteLine(sum);// return 21 (sum)
expr.SetFomular("average(2,3,16)");
decimal average = expr.Eval();
Console.WriteLine(average);// return 7 (average)
}
}
```
## Round, floor, ceiling
```cs
using System;
using org.matheval;
public class Program
{
public static void Main()
{
Expression expr = new Expression("ROUND(2.149, 1)");
Object value = expr.Eval();
Console.WriteLine("ROUND(2.149, 1) = "+value); //return 2.1
expr = new Expression("FLOOR(2.149)");
value = expr.Eval();
Console.WriteLine("FLOOR(2.149) = "+value); //return 2
expr = new Expression("FLOOR(3.7,2)");
value = expr.Eval();
Console.WriteLine("FLOOR(3.7,2) = "+value); //return 2
expr = new Expression("CEILING(2.149)");
value = expr.Eval();
Console.WriteLine("CEILING(2.149) = "+value); //return 3
expr = new Expression("CEILING(1.5, 0.1)");
value = expr.Eval();
Console.WriteLine("CEILING(1.5, 0.1) = "+value); //return 1.5
}
}
```
## Trigonometry
```cs
Expression expr = new Expression('SIN(PI())^2+COS(PI())^2');
Object value = expr.Eval(); //return 1
```
```cs
Expression expr = new Expression("sin(a) - cos(a) = SQRT(2) * sin(a - pi / 4)");
bool value = expr.Bind("a", Math.PI/5).Eval(); //return true
```
```cs
using System;
using org.matheval;
public class Program
{
public static void Main()
{
Expression expr = new Expression("tan(a)^3-((3*sin(a)-sin(3*a))/(3*cos(a)+cos(3*a)))");
Decimal value = expr.Bind("a", Math.PI/6).Eval();
Console.WriteLine(value); //return 0
}
}
```
## Unary operator
```cs
Expression expr = new Expression("3--2+--3-(-(++2))");
Object value = expr.Eval(); //return 10
```
## Deal with string
```cs
using System;
using org.matheval;
public class Program
{
public static void Main()
{
Expression taxExpr = new Expression("IF(LOWER(TAX_CODE)='vat',amount*10/100,IF(LOWER(TAX_CODE)='gst',amount*15/100,0))");
taxExpr.Bind("TAX_CODE","GST");
taxExpr.Bind("amount", 5005m);
Decimal value = taxExpr.Eval();
Console.WriteLine(value);
}
}
```
## Left, right
```cs
Expression expr = new Expression("IF(VALUE(LEFT(date,4))<2020,'n/a','generation of ' & LEFT(date,4))");
expr.Bind("date", "2022-01-20");
String value = expr.Eval();
```
## Calculate tax
```cs
Expression taxExpr = new Expression("IF(LOWER(TAX_CODE)='vat',amount*10/100,IF(LOWER(TAX_CODE)='gst',amount*15/100,0))");
taxExpr.Bind("TAX_CODE","GST");
taxExpr.Bind("amount", 5005m);
Decimal value = taxExpr.Eval();
```
## Concatenate strings
```cs
using System;
using org.matheval;
public class Program
{
public static void Main()
{
Expression expr = new Expression("CONCAT('The United States of ', 'America')");
String value = expr.Eval();
Console.WriteLine(value);//The United States of America
}
}
```
## Datetime
December 30, 1899 date system
We use 1899 date system, the first day that is supported is December 30, 1899. Any date you supply to this library will be converted into a serial number that represents the number of elapsed days starting from December 30, 1899. Look at the sample below:
```cs
Expression expr = new Expression("DATETIME(2025,01,02,12,11,10)");
Decimal serialDate = expr.Eval(); // return 45659.507755 (days elapsed from December 30, 1899)
DateTime datetime = expr.Eval(); // return 2025/01/02 12:11:10
```
## Setting holidays and weekend for expression context
```cs
Expression expr = new Expression("NETWORKDAYS(B5,C5)");
expr.SetHolidays(
new DateTime[] {
new DateTime(2017,11,23),
new DateTime(2017, 12, 25),
new DateTime(2018, 1, 1)
}
);
expr.SetWeekends(new Int32[] { 1, 2, 3 }); //Sunday = 0, ..., Saturday = 6
expr.Bind("B5", new DateTime(2017, 1, 15));
expr.Bind("C5", new DateTime(2018, 1, 21));
Decimal value = expr.Eval(); //return 212
```
## Calculate networkday
```cs
Expression expr = new Expression("NETWORKDAYS(DATEVALUE('2021-03-30'),DATEVALUE('2022-05-16'))");
int value = expr.Eval(); // return 295
```
```cs
Expression expr = new Expression("NETWORKDAYS(startdate,enddate)");
expr.Bind("startdate", new DateTime(2021, 08, 11));
expr.Bind("enddate", new DateTime(2021, 10, 4));
Object value = expr.Eval(); // return 39
```
## Calculates the number of days, months, or years between two dates.
```cs
Expression expr = new Expression("DATEDIF(DATEVALUE('2021-01-31'),DATEVALUE('2029-08-29'),'Y')");
Object value = expr.Eval(); // return 8
```
```cs
Expression expr = new Expression("DATEDIF(DATEVALUE('2021-01-31'),DATEVALUE('2029-08-29'),'M')");
Object value = expr.Eval(); // return 102
```
```cs
Expression expr = new Expression("DATEDIF(DATEVALUE('2021-01-31'),DATEVALUE('2029-08-29'),'D')");
Object value = expr.Eval(); // return 3132
```
```cs
Expression expr = new Expression("DATEDIF(DATEVALUE('2021-01-31'),DATEVALUE('2029-08-29'),'MD')");
Object value = expr.Eval(); // return 29
```
## Calculates the number of days, hours, mins between two datetime.
```cs
Expression expr = new Expression("DATETIME(2021,2,28,15,50,0)-DATETIME(2021,2,21,23,0,0)");
Decimal value = expr.Eval(); // return 6.70139 (days)
```
```cs
Expression expr = new Expression("(DATETIME(2021,2,28,15,50,0)-DATETIME(2021,2,21,23,0,0))*24");
Decimal value = expr.Eval(); // return 160.8 (hours)
```
```cs
Expression expr = new Expression("(DATETIME(2021,2,28,15,50,0)-DATETIME(2021,2,21,23,0,0))*24*60");
Decimal value = expr.Eval(); // return 9650 (mins)
```
## Calculates the number of days, hours, mins between two timespan.
```cs
Expression expr = new Expression("DATETIME(2021,2,28,15,50,0)-DATETIME(2021,2,21,23,0,0)");
Object value = expr.Eval(); // return 6.701389 (days)
```
## Substract, add datetime
```cs
Expression expr = new Expression("DATETIME(2021,2,28,15,50,0)-DATETIME(2021,2,21,23,0,0)");
Object value = expr.Eval(); // return 6.701389 (days)
```
```cs
Expression expr = new Expression("DATE(2021,2,28)-DATE(2021,2,21)");
Object value = expr.Eval(); // return 7 (days)
```
```cs
Expression expr = new Expression("DATE(2021,9,20)+3");
DateTime value = expr.Eval(); // return 2021-09-23
```
```cs
Expression expr = new Expression("TIME(10,10,0)+TIME(10,10,0)");
TimeSpan value = expr.Eval(); // return 20:20:00
```
## License
MIT license