Char.IsHighSurrogate Method

Reference

Definition

Namespace:: System

Assembly:: System.Runtime.dll

Assembly:: mscorlib.dll

Assembly:: netstandard.dll

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

Indicates whether the specified Char object is a high surrogate.

Overloads

IsHighSurrogate(Char)	Indicates whether the specified Char object is a high surrogate.
IsHighSurrogate(String, Int32)	Indicates whether the Char object at the specified position in a string is a high surrogate.

Examples

The following code example demonstrates the IsHighSurrogate, IsLowSurrogate, and IsSurrogatePair methods.

// This example demonstrates the Char.IsLowSurrogate() method
//                                    IsHighSurrogate() method
//                                    IsSurrogatePair() method
using namespace System;
int main()
{
   Char cHigh = L'\xD800';
   Char cLow = L'\xDC00';
   array<Char>^temp0 = {L'a',L'\xD800',L'\xDC00',L'z'};
   String^ s1 = gcnew String( temp0 );
   String^ divider = String::Concat( Environment::NewLine, gcnew String( '-',70 ), Environment::NewLine );
   Console::WriteLine();
   Console::WriteLine( "Hexadecimal code point of the character, cHigh: {0:X4}", (int)cHigh );
   Console::WriteLine( "Hexadecimal code point of the character, cLow:  {0:X4}", (int)cLow );
   Console::WriteLine();
   Console::WriteLine( "Characters in string, s1: 'a', high surrogate, low surrogate, 'z'" );
   Console::WriteLine( "Hexadecimal code points of the characters in string, s1: " );
   for ( int i = 0; i < s1->Length; i++ )
   {
      Console::WriteLine( "s1[{0}] = {1:X4} ", i, (int)s1[ i ] );
   }
   Console::WriteLine( divider );
   Console::WriteLine( "Is each of the following characters a high surrogate?" );
   Console::WriteLine( "A1) cLow?  - {0}", Char::IsHighSurrogate( cLow ) );
   Console::WriteLine( "A2) cHigh? - {0}", Char::IsHighSurrogate( cHigh ) );
   Console::WriteLine( "A3) s1[0]? - {0}", Char::IsHighSurrogate( s1, 0 ) );
   Console::WriteLine( "A4) s1[1]? - {0}", Char::IsHighSurrogate( s1, 1 ) );
   Console::WriteLine( divider );
   Console::WriteLine( "Is each of the following characters a low surrogate?" );
   Console::WriteLine( "B1) cLow?  - {0}", Char::IsLowSurrogate( cLow ) );
   Console::WriteLine( "B2) cHigh? - {0}", Char::IsLowSurrogate( cHigh ) );
   Console::WriteLine( "B3) s1[0]? - {0}", Char::IsLowSurrogate( s1, 0 ) );
   Console::WriteLine( "B4) s1[2]? - {0}", Char::IsLowSurrogate( s1, 2 ) );
   Console::WriteLine( divider );
   Console::WriteLine( "Is each of the following pairs of characters a surrogate pair?" );
   Console::WriteLine( "C1) cHigh and cLow?  - {0}", Char::IsSurrogatePair( cHigh, cLow ) );
   Console::WriteLine( "C2) s1[0] and s1[1]? - {0}", Char::IsSurrogatePair( s1, 0 ) );
   Console::WriteLine( "C3) s1[1] and s1[2]? - {0}", Char::IsSurrogatePair( s1, 1 ) );
   Console::WriteLine( "C4) s1[2] and s1[3]? - {0}", Char::IsSurrogatePair( s1, 2 ) );
   Console::WriteLine( divider );
}

/*
This example produces the following results:

Hexadecimal code point of the character, cHigh: D800
Hexadecimal code point of the character, cLow:  DC00

Characters in string, s1: 'a', high surrogate, low surrogate, 'z'
Hexadecimal code points of the characters in string, s1:
s1[0] = 0061
s1[1] = D800
s1[2] = DC00
s1[3] = 007A

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

Is each of the following characters a high surrogate?
A1) cLow?  - False
A2) cHigh? - True
A3) s1[0]? - False
A4) s1[1]? - True

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

Is each of the following characters a low surrogate?
B1) cLow?  - True
B2) cHigh? - False
B3) s1[0]? - False
B4) s1[2]? - True

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

Is each of the following pairs of characters a surrogate pair?
C1) cHigh and cLow?  - True
C2) s1[0] and s1[1]? - False
C3) s1[1] and s1[2]? - True
C4) s1[2] and s1[3]? - False

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

*/

// This example demonstrates the Char.IsLowSurrogate() method
//                                    IsHighSurrogate() method
//                                    IsSurrogatePair() method
using System;

class Sample
{
    public static void Main()
    {
    char cHigh = '\uD800';
    char cLow  = '\uDC00';
    string s1  = new String(new char[] {'a', '\uD800', '\uDC00', 'z'});
    string divider = String.Concat( Environment.NewLine, new String('-', 70),
                                    Environment.NewLine);

    Console.WriteLine();
    Console.WriteLine("Hexadecimal code point of the character, cHigh: {0:X4}", (int)cHigh);
    Console.WriteLine("Hexadecimal code point of the character, cLow:  {0:X4}", (int)cLow);
    Console.WriteLine();
    Console.WriteLine("Characters in string, s1: 'a', high surrogate, low surrogate, 'z'");
    Console.WriteLine("Hexadecimal code points of the characters in string, s1: ");
    for(int i = 0; i < s1.Length; i++)
        {
        Console.WriteLine("s1[{0}] = {1:X4} ", i, (int)s1[i]);
        }
    Console.WriteLine(divider);

    Console.WriteLine("Is each of the following characters a high surrogate?");
    Console.WriteLine("A1) cLow?  - {0}", Char.IsHighSurrogate(cLow));
    Console.WriteLine("A2) cHigh? - {0}", Char.IsHighSurrogate(cHigh));
    Console.WriteLine("A3) s1[0]? - {0}", Char.IsHighSurrogate(s1, 0));
    Console.WriteLine("A4) s1[1]? - {0}", Char.IsHighSurrogate(s1, 1));
    Console.WriteLine(divider);

    Console.WriteLine("Is each of the following characters a low surrogate?");
    Console.WriteLine("B1) cLow?  - {0}", Char.IsLowSurrogate(cLow));
    Console.WriteLine("B2) cHigh? - {0}", Char.IsLowSurrogate(cHigh));
    Console.WriteLine("B3) s1[0]? - {0}", Char.IsLowSurrogate(s1, 0));
    Console.WriteLine("B4) s1[2]? - {0}", Char.IsLowSurrogate(s1, 2));
    Console.WriteLine(divider);

    Console.WriteLine("Is each of the following pairs of characters a surrogate pair?");
    Console.WriteLine("C1) cHigh and cLow?  - {0}", Char.IsSurrogatePair(cHigh, cLow));
    Console.WriteLine("C2) s1[0] and s1[1]? - {0}", Char.IsSurrogatePair(s1, 0));
    Console.WriteLine("C3) s1[1] and s1[2]? - {0}", Char.IsSurrogatePair(s1, 1));
    Console.WriteLine("C4) s1[2] and s1[3]? - {0}", Char.IsSurrogatePair(s1, 2));
    Console.WriteLine(divider);
    }
}
/*
This example produces the following results:

Hexadecimal code point of the character, cHigh: D800
Hexadecimal code point of the character, cLow:  DC00

Characters in string, s1: 'a', high surrogate, low surrogate, 'z'
Hexadecimal code points of the characters in string, s1:
s1[0] = 0061
s1[1] = D800
s1[2] = DC00
s1[3] = 007A

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

Is each of the following characters a high surrogate?
A1) cLow?  - False
A2) cHigh? - True
A3) s1[0]? - False
A4) s1[1]? - True

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

Is each of the following characters a low surrogate?
B1) cLow?  - True
B2) cHigh? - False
B3) s1[0]? - False
B4) s1[2]? - True

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

Is each of the following pairs of characters a surrogate pair?
C1) cHigh and cLow?  - True
C2) s1[0] and s1[1]? - False
C3) s1[1] and s1[2]? - True
C4) s1[2] and s1[3]? - False

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

*/

// This example demonstrates the Char.IsLowSurrogate() method
//                                    IsHighSurrogate() method
//                                    IsSurrogatePair() method
open System

let cHigh = '\uD800'
let cLow  = '\uDC00'
let s1 = String [| 'a'; '\uD800'; '\uDC00'; 'z' |]
let divider = String.Concat(Environment.NewLine, String('-', 70), Environment.NewLine)

printfn $"""
Hexadecimal code point of the character, cHigh: {int cHigh:X4}
Hexadecimal code point of the character, cLow:  {int cLow:X4}

Characters in string, s1: 'a', high surrogate, low surrogate, 'z'
Hexadecimal code points of the characters in string, s1: """

for i = 0 to s1.Length - 1 do
    printfn $"s1[{i}] = {int s1[i]:X4} "

printfn $"""{divider}
Is each of the following characters a high surrogate?
A1) cLow?  - {Char.IsHighSurrogate cLow}
A2) cHigh? - {Char.IsHighSurrogate cHigh}
A3) s1[0]? - {Char.IsHighSurrogate(s1, 0)}
A4) s1[1]? - {Char.IsHighSurrogate(s1, 1)}
{divider}"""

printfn $"""Is each of the following characters a low surrogate?
B1) cLow?  - {Char.IsLowSurrogate cLow}
B2) cHigh? - {Char.IsLowSurrogate cHigh}
B3) s1[0]? - {Char.IsLowSurrogate(s1, 0)}
B4) s1[2]? - {Char.IsLowSurrogate(s1, 2)}
{divider}"""

printfn $"""Is each of the following pairs of characters a surrogate pair?
C1) cHigh and cLow?  - {Char.IsSurrogatePair(cHigh, cLow)}
C2) s1[0] and s1[1]? - {Char.IsSurrogatePair(s1, 0)}
C3) s1[1] and s1[2]? - {Char.IsSurrogatePair(s1, 1)}
C4) s1[2] and s1[3]? - {Char.IsSurrogatePair(s1, 2)}"
{divider}"""

// This example produces the following results:
//
// Hexadecimal code point of the character, cHigh: D800
// Hexadecimal code point of the character, cLow:  DC00
//
// Characters in string, s1: 'a', high surrogate, low surrogate, 'z'
// Hexadecimal code points of the characters in string, s1:
// s1[0] = 0061
// s1[1] = D800
// s1[2] = DC00
// s1[3] = 007A
//
// ----------------------------------------------------------------------
//
// Is each of the following characters a high surrogate?
// A1) cLow?  - False
// A2) cHigh? - True
// A3) s1[0]? - False
// A4) s1[1]? - True
//
// ----------------------------------------------------------------------
//
// Is each of the following characters a low surrogate?
// B1) cLow?  - True
// B2) cHigh? - False
// B3) s1[0]? - False
// B4) s1[2]? - True
//
// ----------------------------------------------------------------------
//
// Is each of the following pairs of characters a surrogate pair?
// C1) cHigh and cLow?  - True
// C2) s1[0] and s1[1]? - False
// C3) s1[1] and s1[2]? - True
// C4) s1[2] and s1[3]? - False
//
// ----------------------------------------------------------------------

' This example demonstrates the Char.IsLowSurrogate() method
'                                    IsHighSurrogate() method
'                                    IsSurrogatePair() method
Class Sample
   Public Shared Sub Main()
      Dim cHigh As Char = ChrW(&HD800)
      Dim cLow  As Char = ChrW(&HDC00)
      Dim s1 = New [String](New Char() {"a"c, ChrW(&HD800), ChrW(&HDC00), "z"c})
      Dim divider As String = [String].Concat(Environment.NewLine, _
                                              New [String]("-"c, 70), _
                                              Environment.NewLine)
      
      Console.WriteLine()
      Console.WriteLine("Hexadecimal code point of the character, cHigh: {0:X4}", AscW(cHigh))
      Console.WriteLine("Hexadecimal code point of the character, cLow:  {0:X4}", AscW(cLow))
      Console.WriteLine()
      Console.WriteLine("Characters in string, s1: 'a', high surrogate, low surrogate, 'z'")
      Console.WriteLine("Hexadecimal code points of the characters in string, s1: ")
      Dim i As Integer
      For i = 0 To s1.Length - 1
         Console.WriteLine("s1({0}) = {1:X4} ", i, AscW(s1.Chars(i)))
      Next i
      Console.WriteLine(divider)
      
      Console.WriteLine("Is each of the following characters a high surrogate?")
      Console.WriteLine("A1) cLow?  - {0}", [Char].IsHighSurrogate(cLow))
      Console.WriteLine("A2) cHigh? - {0}", [Char].IsHighSurrogate(cHigh))
      Console.WriteLine("A3) s1(0)? - {0}", [Char].IsHighSurrogate(s1, 0))
      Console.WriteLine("A4) s1(1)? - {0}", [Char].IsHighSurrogate(s1, 1))
      Console.WriteLine(divider)
      
      Console.WriteLine("Is each of the following characters a low surrogate?")
      Console.WriteLine("B1) cLow?  - {0}", [Char].IsLowSurrogate(cLow))
      Console.WriteLine("B2) cHigh? - {0}", [Char].IsLowSurrogate(cHigh))
      Console.WriteLine("B3) s1(0)? - {0}", [Char].IsLowSurrogate(s1, 0))
      Console.WriteLine("B4) s1(2)? - {0}", [Char].IsLowSurrogate(s1, 2))
      Console.WriteLine(divider)
      
      Console.WriteLine("Is each of the following pairs of characters a surrogate pair?")
      Console.WriteLine("C1) cHigh and cLow?  - {0}", [Char].IsSurrogatePair(cHigh, cLow))
      Console.WriteLine("C2) s1(0) and s1(1)? - {0}", [Char].IsSurrogatePair(s1, 0))
      Console.WriteLine("C3) s1(1) and s1(2)? - {0}", [Char].IsSurrogatePair(s1, 1))
      Console.WriteLine("C4) s1(2) and s1(3)? - {0}", [Char].IsSurrogatePair(s1, 2))
      Console.WriteLine(divider)
   End Sub
End Class
'
'This example produces the following results:
'
'Hexadecimal code point of the character, cHigh: D800
'Hexadecimal code point of the character, cLow:  DC00
'
'Characters in string, s1: 'a', high surrogate, low surrogate, 'z'
'Hexadecimal code points of the characters in string, s1:
's1(0) = 0061
's1(1) = D800
's1(2) = DC00
's1(3) = 007A
'
'----------------------------------------------------------------------
'
'Is each of the following characters a high surrogate?
'A1) cLow?  - False
'A2) cHigh? - True
'A3) s1(0)? - False
'A4) s1(1)? - True
'
'----------------------------------------------------------------------
'
'Is each of the following characters a low surrogate?
'B1) cLow?  - True
'B2) cHigh? - False
'B3) s1(0)? - False
'B4) s1(2)? - True
'
'----------------------------------------------------------------------
'
'Is each of the following pairs of characters a surrogate pair?
'C1) cHigh and cLow?  - True
'C2) s1(0) and s1(1)? - False
'C3) s1(1) and s1(2)? - True
'C4) s1(2) and s1(3)? - False
'
'----------------------------------------------------------------------
'

IsHighSurrogate(Char)

Source:: Char.cs

Source:: Char.cs

Source:: Char.cs

Indicates whether the specified Char object is a high surrogate.

public:
 static bool IsHighSurrogate(char c);

public static bool IsHighSurrogate (char c);

static member IsHighSurrogate : char -> bool

Public Shared Function IsHighSurrogate (c As Char) As Boolean

Parameters

c: Char

The Unicode character to evaluate.

Returns

Boolean

true if the numeric value of the c parameter ranges from U+D800 through U+DBFF; otherwise, false.

Remarks

In addition to representing single characters using a 16-bit code point, UTF-16 encoding allows abstract characters to be represented using two 16-bit code points, which is known as a surrogate pair. The first element in this pair is the high surrogate. Its code point can range from U+D800 to U+DBFF. An individual surrogate has no interpretation of its own; it is meaningful only when used as part of a surrogate pair.

Applies to

IsHighSurrogate(String, Int32)

Source:: Char.cs

Source:: Char.cs

Source:: Char.cs

Indicates whether the Char object at the specified position in a string is a high surrogate.

public:
 static bool IsHighSurrogate(System::String ^ s, int index);

public static bool IsHighSurrogate (string s, int index);

static member IsHighSurrogate : string * int -> bool

Public Shared Function IsHighSurrogate (s As String, index As Integer) As Boolean

Parameters

s: String

A string.

index: Int32

The position of the character to evaluate in s.

Returns

Boolean

true if the numeric value of the specified character in the s parameter ranges from U+D800 through U+DBFF; otherwise, false.

Exceptions

ArgumentNullException

s is null.

ArgumentOutOfRangeException

index is not a position within s.

Remarks

The index parameter is zero-based.

Applies to

Sdílet prostřednictvím

Char.IsHighSurrogate Method

Definition

Overloads

Examples

IsHighSurrogate(Char)

Parameters

Returns

Remarks

See also

Applies to

IsHighSurrogate(String, Int32)

Parameters

Returns

Exceptions

Remarks

See also

Applies to

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