Skip to main content
.NET Framework Class Library
StringIsNormalized Method

Indicates whether this string is in Unicode normalization form C.

Namespace:   System
Assembly:  mscorlib (in mscorlib.dll)
Syntax
Public Function IsNormalized As [%$TOPIC/0wcxb622_en-us_VS_110_1_0_0_0_0%]
public [%$TOPIC/0wcxb622_en-us_VS_110_1_0_1_0_0%] IsNormalized()
public:
[%$TOPIC/0wcxb622_en-us_VS_110_1_0_2_0_0%] IsNormalized()
member IsNormalized : unit -> [%$TOPIC/0wcxb622_en-us_VS_110_1_0_3_0_0%]
public function IsNormalized() : [%$TOPIC/0wcxb622_en-us_VS_110_1_0_4_0_0%]

Return Value

Type: SystemBoolean
true if this string is in normalization form C; otherwise, false.
Exceptions
ExceptionCondition
ArgumentException

The current instance contains invalid Unicode characters.

Remarks

Some Unicode characters have multiple equivalent binary representations consisting of sets of combining and/or composite Unicode characters. The existence of multiple representations for a single character complicates searching, sorting, matching, and other operations.

The Unicode standard defines a process called normalization that returns one binary representation when given any of the equivalent binary representations of a character. Normalization can be performed with several algorithms, called normalization forms, that obey different rules. The .NET Framework currently supports normalization forms C, D, KC, and KD.

For a description of supported Unicode normalization forms, see System.TextNormalizationForm.

Notes to Callers

The IsNormalized method returns false as soon as it encounters the first non-normalized character in a string. Therefore, if a string contains non-normalized characters followed by invalid Unicode characters, the Normalize method will throw an ArgumentException although IsNormalized returns false.

Examples

The following example determines whether a string is successfully normalized to various normalization forms.

Imports System.Text

Class Example
   Public Shared Sub Main()
      ' Character c; combining characters acute and cedilla; character 3/4 
      Dim s1 = New [String](New Char() {ChrW(&H0063), ChrW(&H0301), ChrW(&H0327), ChrW(&H00BE)})
      Dim s2 As String = Nothing 
      Dim divider = New [String]("-"c, 80)
      divider = [String].Concat(Environment.NewLine, divider, Environment.NewLine)

      Show("s1", s1)
      Console.WriteLine()
      Console.WriteLine("U+0063 = LATIN SMALL LETTER C")
      Console.WriteLine("U+0301 = COMBINING ACUTE ACCENT")
      Console.WriteLine("U+0327 = COMBINING CEDILLA")
      Console.WriteLine("U+00BE = VULGAR FRACTION THREE QUARTERS")

      Console.WriteLine(divider)

      Console.WriteLine("A1) Is s1 normalized to the default form (Form C)?: {0}", s1.IsNormalized())
      Console.WriteLine("A2) Is s1 normalized to Form C?:  {0}", s1.IsNormalized(NormalizationForm.FormC))
      Console.WriteLine("A3) Is s1 normalized to Form D?:  {0}", s1.IsNormalized(NormalizationForm.FormD))
      Console.WriteLine("A4) Is s1 normalized to Form KC?: {0}", s1.IsNormalized(NormalizationForm.FormKC))
      Console.WriteLine("A5) Is s1 normalized to Form KD?: {0}", s1.IsNormalized(NormalizationForm.FormKD))

      Console.WriteLine(divider)

      Console.WriteLine("Set string s2 to each normalized form of string s1.")
      Console.WriteLine()
      Console.WriteLine("U+1E09 = LATIN SMALL LETTER C WITH CEDILLA AND ACUTE")
      Console.WriteLine("U+0033 = DIGIT THREE")
      Console.WriteLine("U+2044 = FRACTION SLASH")
      Console.WriteLine("U+0034 = DIGIT FOUR")
      Console.WriteLine(divider)

      s2 = s1.Normalize()
      Console.Write("B1) Is s2 normalized to the default form (Form C)?: ")
      Console.WriteLine(s2.IsNormalized())
      Show("s2", s2)
      Console.WriteLine()

      s2 = s1.Normalize(NormalizationForm.FormC)
      Console.Write("B2) Is s2 normalized to Form C?: ")
      Console.WriteLine(s2.IsNormalized(NormalizationForm.FormC))
      Show("s2", s2)
      Console.WriteLine()

      s2 = s1.Normalize(NormalizationForm.FormD)
      Console.Write("B3) Is s2 normalized to Form D?: ")
      Console.WriteLine(s2.IsNormalized(NormalizationForm.FormD))
      Show("s2", s2)
      Console.WriteLine()

      s2 = s1.Normalize(NormalizationForm.FormKC)
      Console.Write("B4) Is s2 normalized to Form KC?: ")
      Console.WriteLine(s2.IsNormalized(NormalizationForm.FormKC))
      Show("s2", s2)
      Console.WriteLine()

      s2 = s1.Normalize(NormalizationForm.FormKD)
      Console.Write("B5) Is s2 normalized to Form KD?: ")
      Console.WriteLine(s2.IsNormalized(NormalizationForm.FormKD))
      Show("s2", s2)
      Console.WriteLine()
   End Sub  

   Private Shared Sub Show(title As String, s As String)
      Console.Write("Characters in string {0} = ", title)
      For Each x As Char In s
         Console.Write("{0:X4} ", AscW(x))
      Next 
      Console.WriteLine()
   End Sub  
End Class  
'This example produces the following results: 
' 
'Characters in string s1 = 0063 0301 0327 00BE 
' 
'U+0063 = LATIN SMALL LETTER C 
'U+0301 = COMBINING ACUTE ACCENT 
'U+0327 = COMBINING CEDILLA 
'U+00BE = VULGAR FRACTION THREE QUARTERS 
' 
'-------------------------------------------------------------------------------- 
' 
'A1) Is s1 normalized to the default form (Form C)?: False 
'A2) Is s1 normalized to Form C?:  False 
'A3) Is s1 normalized to Form D?:  False 
'A4) Is s1 normalized to Form KC?: False 
'A5) Is s1 normalized to Form KD?: False 
' 
'-------------------------------------------------------------------------------- 
' 
'Set string s2 to each normalized form of string s1. 
' 
'U+1E09 = LATIN SMALL LETTER C WITH CEDILLA AND ACUTE 
'U+0033 = DIGIT THREE 
'U+2044 = FRACTION SLASH 
'U+0034 = DIGIT FOUR 
' 
'-------------------------------------------------------------------------------- 
' 
'B1) Is s2 normalized to the default form (Form C)?: True 
'Characters in string s2 = 1E09 00BE 
' 
'B2) Is s2 normalized to Form C?: True 
'Characters in string s2 = 1E09 00BE 
' 
'B3) Is s2 normalized to Form D?: True 
'Characters in string s2 = 0063 0327 0301 00BE 
' 
'B4) Is s2 normalized to Form KC?: True 
'Characters in string s2 = 1E09 0033 2044 0034 
' 
'B5) Is s2 normalized to Form KD?: True 
'Characters in string s2 = 0063 0327 0301 0033 2044 0034 
'
using System;
using System.Text;

class Example
{
    public static void Main() 
    {
       // Character c; combining characters acute and cedilla; character 3/4 
       string s1 = new String( new char[] {'\u0063', '\u0301', '\u0327', '\u00BE'});
       string s2 = null;
       string divider = new String('-', 80);
       divider = String.Concat(Environment.NewLine, divider, Environment.NewLine);

       Show("s1", s1);
       Console.WriteLine();
       Console.WriteLine("U+0063 = LATIN SMALL LETTER C");
       Console.WriteLine("U+0301 = COMBINING ACUTE ACCENT");
       Console.WriteLine("U+0327 = COMBINING CEDILLA");
       Console.WriteLine("U+00BE = VULGAR FRACTION THREE QUARTERS");
       Console.WriteLine(divider);

       Console.WriteLine("A1) Is s1 normalized to the default form (Form C)?: {0}", 
                                    s1.IsNormalized());
       Console.WriteLine("A2) Is s1 normalized to Form C?:  {0}", 
                                    s1.IsNormalized(NormalizationForm.FormC));
       Console.WriteLine("A3) Is s1 normalized to Form D?:  {0}", 
                                    s1.IsNormalized(NormalizationForm.FormD));
       Console.WriteLine("A4) Is s1 normalized to Form KC?: {0}", 
                                    s1.IsNormalized(NormalizationForm.FormKC));
       Console.WriteLine("A5) Is s1 normalized to Form KD?: {0}", 
                                    s1.IsNormalized(NormalizationForm.FormKD));

       Console.WriteLine(divider);

       Console.WriteLine("Set string s2 to each normalized form of string s1.");
       Console.WriteLine();
       Console.WriteLine("U+1E09 = LATIN SMALL LETTER C WITH CEDILLA AND ACUTE");
       Console.WriteLine("U+0033 = DIGIT THREE");
       Console.WriteLine("U+2044 = FRACTION SLASH");
       Console.WriteLine("U+0034 = DIGIT FOUR");
       Console.WriteLine(divider);

       s2 = s1.Normalize();
       Console.Write("B1) Is s2 normalized to the default form (Form C)?: ");
       Console.WriteLine(s2.IsNormalized());
       Show("s2", s2);
       Console.WriteLine();

       s2 = s1.Normalize(NormalizationForm.FormC);
       Console.Write("B2) Is s2 normalized to Form C?: ");
       Console.WriteLine(s2.IsNormalized(NormalizationForm.FormC));
       Show("s2", s2);
       Console.WriteLine();

       s2 = s1.Normalize(NormalizationForm.FormD);
       Console.Write("B3) Is s2 normalized to Form D?: ");
       Console.WriteLine(s2.IsNormalized(NormalizationForm.FormD));
       Show("s2", s2);
       Console.WriteLine();

       s2 = s1.Normalize(NormalizationForm.FormKC);
       Console.Write("B4) Is s2 normalized to Form KC?: ");
       Console.WriteLine(s2.IsNormalized(NormalizationForm.FormKC));
       Show("s2", s2);
       Console.WriteLine();

       s2 = s1.Normalize(NormalizationForm.FormKD);
       Console.Write("B5) Is s2 normalized to Form KD?: ");
       Console.WriteLine(s2.IsNormalized(NormalizationForm.FormKD));
       Show("s2", s2);
       Console.WriteLine();
    }

    private static void Show(string title, string s)
    {
       Console.Write("Characters in string {0} = ", title);
       foreach(short x in s) {
           Console.Write("{0:X4} ", x);
       }
       Console.WriteLine();
    }
}
/*
This example produces the following results:

Characters in string s1 = 0063 0301 0327 00BE

U+0063 = LATIN SMALL LETTER C
U+0301 = COMBINING ACUTE ACCENT
U+0327 = COMBINING CEDILLA
U+00BE = VULGAR FRACTION THREE QUARTERS

--------------------------------------------------------------------------------

A1) Is s1 normalized to the default form (Form C)?: False
A2) Is s1 normalized to Form C?:  False
A3) Is s1 normalized to Form D?:  False
A4) Is s1 normalized to Form KC?: False
A5) Is s1 normalized to Form KD?: False

--------------------------------------------------------------------------------

Set string s2 to each normalized form of string s1.

U+1E09 = LATIN SMALL LETTER C WITH CEDILLA AND ACUTE
U+0033 = DIGIT THREE
U+2044 = FRACTION SLASH
U+0034 = DIGIT FOUR

--------------------------------------------------------------------------------

B1) Is s2 normalized to the default form (Form C)?: True
Characters in string s2 = 1E09 00BE

B2) Is s2 normalized to Form C?: True
Characters in string s2 = 1E09 00BE

B3) Is s2 normalized to Form D?: True
Characters in string s2 = 0063 0327 0301 00BE

B4) Is s2 normalized to Form KC?: True
Characters in string s2 = 1E09 0033 2044 0034

B5) Is s2 normalized to Form KD?: True
Characters in string s2 = 0063 0327 0301 0033 2044 0034

*/
using namespace System;
using namespace System::Text;

void Show( String^ title, String^ s )
{
   Console::Write( "Characters in string {0} = ", title );
   for each (short x in s) {
      Console::Write("{0:X4} ", x);
   }
   Console::WriteLine();
}

int main()
{

   // Character c; combining characters acute and cedilla; character 3/4 
   array<Char>^temp0 = {L'c',L'\u0301',L'\u0327',L'\u00BE'};
   String^ s1 = gcnew String( temp0 );
   String^ s2 = nullptr;
   String^ divider = gcnew String( '-',80 );
   divider = String::Concat( Environment::NewLine, divider, Environment::NewLine );

   Show( "s1", s1 );
   Console::WriteLine();
   Console::WriteLine( "U+0063 = LATIN SMALL LETTER C" );
   Console::WriteLine( "U+0301 = COMBINING ACUTE ACCENT" );
   Console::WriteLine( "U+0327 = COMBINING CEDILLA" );
   Console::WriteLine( "U+00BE = VULGAR FRACTION THREE QUARTERS" );
   Console::WriteLine( divider );
   Console::WriteLine( "A1) Is s1 normalized to the default form (Form C)?: {0}", s1->IsNormalized() );
   Console::WriteLine( "A2) Is s1 normalized to Form C?:  {0}", s1->IsNormalized( NormalizationForm::FormC ) );
   Console::WriteLine( "A3) Is s1 normalized to Form D?:  {0}", s1->IsNormalized( NormalizationForm::FormD ) );
   Console::WriteLine( "A4) Is s1 normalized to Form KC?: {0}", s1->IsNormalized( NormalizationForm::FormKC ) );
   Console::WriteLine( "A5) Is s1 normalized to Form KD?: {0}", s1->IsNormalized( NormalizationForm::FormKD ) );
   Console::WriteLine( divider );
   Console::WriteLine( "Set string s2 to each normalized form of string s1." );
   Console::WriteLine();
   Console::WriteLine( "U+1E09 = LATIN SMALL LETTER C WITH CEDILLA AND ACUTE" );
   Console::WriteLine( "U+0033 = DIGIT THREE" );
   Console::WriteLine( "U+2044 = FRACTION SLASH" );
   Console::WriteLine( "U+0034 = DIGIT FOUR" );
   Console::WriteLine( divider );
   s2 = s1->Normalize();
   Console::Write( "B1) Is s2 normalized to the default form (Form C)?: " );
   Console::WriteLine( s2->IsNormalized() );
   Show( "s2", s2 );
   Console::WriteLine();
   s2 = s1->Normalize( NormalizationForm::FormC );
   Console::Write( "B2) Is s2 normalized to Form C?: " );
   Console::WriteLine( s2->IsNormalized( NormalizationForm::FormC ) );
   Show( "s2", s2 );
   Console::WriteLine();
   s2 = s1->Normalize( NormalizationForm::FormD );
   Console::Write( "B3) Is s2 normalized to Form D?: " );
   Console::WriteLine( s2->IsNormalized( NormalizationForm::FormD ) );
   Show( "s2", s2 );
   Console::WriteLine();
   s2 = s1->Normalize( NormalizationForm::FormKC );
   Console::Write( "B4) Is s2 normalized to Form KC?: " );
   Console::WriteLine( s2->IsNormalized( NormalizationForm::FormKC ) );
   Show( "s2", s2 );
   Console::WriteLine();
   s2 = s1->Normalize( NormalizationForm::FormKD );
   Console::Write( "B5) Is s2 normalized to Form KD?: " );
   Console::WriteLine( s2->IsNormalized( NormalizationForm::FormKD ) );
   Show( "s2", s2 );
   Console::WriteLine();
}

/*
This example produces the following results:

Characters in string s1 = 0063 0301 0327 00BE

U+0063 = LATIN SMALL LETTER C
U+0301 = COMBINING ACUTE ACCENT
U+0327 = COMBINING CEDILLA
U+00BE = VULGAR FRACTION THREE QUARTERS

--------------------------------------------------------------------------------

A1) Is s1 normalized to the default form (Form C)?: False
A2) Is s1 normalized to Form C?:  False
A3) Is s1 normalized to Form D?:  False
A4) Is s1 normalized to Form KC?: False
A5) Is s1 normalized to Form KD?: False

--------------------------------------------------------------------------------

Set string s2 to each normalized form of string s1.

U+1E09 = LATIN SMALL LETTER C WITH CEDILLA AND ACUTE
U+0033 = DIGIT THREE
U+2044 = FRACTION SLASH
U+0034 = DIGIT FOUR

--------------------------------------------------------------------------------

B1) Is s2 normalized to the default form (Form C)?: True
Characters in string s2 = 1E09 00BE

B2) Is s2 normalized to Form C?: True
Characters in string s2 = 1E09 00BE

B3) Is s2 normalized to Form D?: True
Characters in string s2 = 0063 0327 0301 00BE

B4) Is s2 normalized to Form KC?: True
Characters in string s2 = 1E09 0033 2044 0034

B5) Is s2 normalized to Form KD?: True
Characters in string s2 = 0063 0327 0301 0033 2044 0034

*/
Version Information

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1