CharUnicodeInfo::GetNumericValue Method (Char)

Gets the numeric value associated with the specified character.

Namespace:  System.Globalization
Assembly:  mscorlib (in mscorlib.dll)

public:
static double GetNumericValue(
	wchar_t ch
)

Parameters

ch
Type: System::Char

The Unicode character for which to get the numeric value.

Return Value

Type: System::Double
The numeric value associated with the specified character.
-or-
-1, if the specified character is not a numeric character.

Numeric value is a Unicode character property that applies only to numeric characters, which include fractions, subscripts, superscripts, Roman numerals, currency numerators, encircled numbers, and script-specific digits. For more information on Unicode characters, see the Unicode Standard.

The GetNumericValue(Char) method assumes that ch corresponds to a single linguistic character and checks whether that character can be converted to a decimal digit. However, some numbers in the Unicode standard are represented by two Char objects that form a surrogate pair. For example, the Aegean numbering system consists of code points U+10107 through U+10133. The following example uses the ConvertFromUtf32 method to instantiate a string that represents AEGEAN NUMBER ONE. As the output from the example shows, the GetNumericValue(Char) method returns -1 if it is passed either a high surrogate or a low surrogate of this character.

No code example is currently available or this language may not be supported.

The following code example shows the values returned by each method for different types of characters.

using namespace System;
using namespace System::Globalization;
void PrintProperties( Char c );
int main()
{
   Console::WriteLine( "                                        c  Num   Dig   Dec   UnicodeCategory" );
   Console::Write( "U+0061 LATIN SMALL LETTER A            " );
   PrintProperties( L'a' );
   Console::Write( "U+0393 GREEK CAPITAL LETTER GAMMA      " );
   PrintProperties( L'\u0393' );
   Console::Write( "U+0039 DIGIT NINE                      " );
   PrintProperties( L'9' );
   Console::Write( "U+00B2 SUPERSCRIPT TWO                 " );
   PrintProperties( L'\u00B2' );
   Console::Write( "U+00BC VULGAR FRACTION ONE QUARTER     " );
   PrintProperties( L'\u00BC' );
   Console::Write( "U+0BEF TAMIL DIGIT NINE                " );
   PrintProperties( L'\u0BEF' );
   Console::Write( "U+0BF0 TAMIL NUMBER TEN                " );
   PrintProperties( L'\u0BF0' );
   Console::Write( "U+0F33 TIBETAN DIGIT HALF ZERO         " );
   PrintProperties( L'\u0F33' );
   Console::Write( "U+2788 CIRCLED SANS-SERIF DIGIT NINE   " );
   PrintProperties( L'\u2788' );
}

void PrintProperties( Char c )
{
   Console::Write( " {0,-3}", c );
   Console::Write( " {0,-5}", CharUnicodeInfo::GetNumericValue( c ) );
   Console::Write( " {0,-5}", CharUnicodeInfo::GetDigitValue( c ) );
   Console::Write( " {0,-5}", CharUnicodeInfo::GetDecimalDigitValue( c ) );
   Console::WriteLine( "{0}", CharUnicodeInfo::GetUnicodeCategory( c ) );
}

/*
This code produces the following output.  Some characters might not display at the console.

                                        c  Num   Dig   Dec   UnicodeCategory
U+0061 LATIN SMALL LETTER A             a   -1    -1    -1   LowercaseLetter
U+0393 GREEK CAPITAL LETTER GAMMA       \u0393   -1    -1    -1   UppercaseLetter
U+0039 DIGIT NINE                       9   9     9     9    DecimalDigitNumber
U+00B2 SUPERSCRIPT TWO                  \u00B2   2     2     2    OtherNumber
U+00BC VULGAR FRACTION ONE QUARTER      \u00BC   0.25  -1    -1   OtherNumber
U+0BEF TAMIL DIGIT NINE                 \u0BEF   9     9     9    DecimalDigitNumber
U+0BF0 TAMIL NUMBER TEN                 \u0BF0   10    -1    -1   OtherNumber
U+0F33 TIBETAN DIGIT HALF ZERO          \u0F33   -0.5  -1    -1   OtherNumber
U+2788 CIRCLED SANS-SERIF DIGIT NINE    \u2788   9     9     -1   OtherNumber

*/

.NET Framework

Supported in: 4.5, 4, 3.5, 3.0, 2.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

.NET for Windows Store apps

Supported in: Windows 8

.NET for Windows Phone apps

Supported in: Windows Phone 8.1, Windows Phone Silverlight 8.1, Windows Phone Silverlight 8

Windows Phone 8.1, Windows Phone 8, Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Was this page helpful?
(1500 characters remaining)
Thank you for your feedback
Show:
© 2014 Microsoft