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Char.IsLowSurrogate Method

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Definition

Namespace:
System
Assembly:
System.Runtime.dll
Assembly:
mscorlib.dll
Assembly:
netstandard.dll

Indicates whether the specified Char object is a low surrogate.

Overloads

IsLowSurrogate(Char)

Indicates whether the specified Char object is a low surrogate.
IsLowSurrogate(String, Int32)

Indicates whether the Char object at the specified position in a string is a low 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
'
'----------------------------------------------------------------------
'

IsLowSurrogate(Char)

Source:
Char.cs
Source:
Char.cs
Source:
Char.cs

Indicates whether the specified Char object is a low surrogate.

public:
 static bool IsLowSurrogate(char c);
public static bool IsLowSurrogate (char c);
static member IsLowSurrogate : char -> bool
Public Shared Function IsLowSurrogate (c As Char) As Boolean

Parameters

c
Char

The character to evaluate.

Returns

Boolean

true if the numeric value of the c parameter ranges from U+DC00 through U+DFFF; 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 second element in this pair is the low surrogate. Its code point can range from U+DC00 to U+DFFF. An individual surrogate has no interpretation of its own; it is meaningful only when used as part of a surrogate pair.

See also

Applies to

IsLowSurrogate(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 low surrogate.

public:
 static bool IsLowSurrogate(System::String ^ s, int index);
public static bool IsLowSurrogate (string s, int index);
static member IsLowSurrogate : string * int -> bool
Public Shared Function IsLowSurrogate (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+DC00 through U+DFFF; otherwise, false.

Exceptions

ArgumentNullException

s is null.

ArgumentOutOfRangeException

index is not a position within s.

Remarks

The index parameter is zero-based.

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 second element in this pair is the low surrogate. Its code point can range from U+DC00 to U+DFFF. An individual surrogate has no interpretation of its own; it is meaningful only when used as part of a surrogate pair.

See also

Applies to