Table of Contents

Values

A value is a terminal token representing a concrete element. This can be:

Integers

They are represented using numbers.

123456

They are evaluated as int. If the value is too big, it will be evaluated as long.

Floating point numbers

Use the dot to define the decimal part.

123.456
.123

They are evaluated as double, unless you use DecimalAsDefault.

Scientific notation

You can use the e to define power of ten (10^).

1.22e1
1e2
1e+2
1e+2
1e-2
.1e-2
1e10

They are evaluated as double, unless you use DecimalAsDefault.

DateTime

Must be enclosed between sharps.

#2008/01/31# // for en-US culture
#08/08/2001 09:30:00#

NCalc uses the current Culture to evaluate them.

TimeSpan

Must be enclosed between sharps.

#20:42:00#

Booleans

Booleans can be either true or false.

true

Strings

Any character between single or double quotes are evaluated as string.

'hello'

greeting("Chers")

You can escape special characters using \, ', \n, \r, \t.

Chars

If you use <xref:ExpressionOptions.AllowCharValues>, single quoted strings are interpreted as char

var expression = new Expression("'g'", ExpressionOptions.AllowCharValues);
var result = expression.Evalutate();
Debug.Assert(result); // 'g' -> System.Char

Guid

NCalc also supports Guid, they can be parsed with or without hyphens.

b1548bd5-2556-4d2a-9f47-bb8d421026dd
getUser(78b1941f4e7941c9bef656fad7326538)

Function

A function is made of a name followed by braces, containing optionally any value as arguments.

  Abs(1)

doSomething(1, 'dummy')

Please read the functions page for details.

Parameters

A parameter as a name, and can be optionally contained inside brackets or double quotes.

  2 + x, 2 + [x]

Please read the parameters page for details.

Lists

Lists are collections of expressions enclosed in parentheses. They are the equivalent of List<LogicalExpression> at CLR.

('Chers', secretOperation(), 3.14)
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