Char.IsSurrogatePair Method (Char, Char)
Indicates whether the two specified Char objects form a surrogate pair.
Assembly: mscorlib (in mscorlib.dll)
Public Shared Function IsSurrogatePair ( highSurrogate As Char, lowSurrogate As Char ) As Boolean
Parameters
- highSurrogate
-
Type:
System.Char
The character to evaluate as the high surrogate of a surrogate pair.
- lowSurrogate
-
Type:
System.Char
The character to evaluate as the low surrogate of a surrogate pair.
Return Value
Type: System.Booleantrue if the numeric value of the highSurrogate parameter ranges from U+D800 through U+DBFF, and the numeric value of the lowSurrogate parameter ranges from U+DC00 through U+DFFF; otherwise, false.
Ordinarily, a single character is represented by a single 16-bit Unicode code unit. UTF-16 encoding also supports surrogate pairs, which allow a single abstract character to be represented by two 16-bit code units. The first code unit, whose value can range from U+D800 to U+DBFF, is the high surrogate. The second code unit, whose value can range from U+DC00 to U+DFFF, is the low surrogate. Individual surrogate code points have no interpretation of their own. For more information about surrogates and the Unicode Standard, see the Unicode home page.
The following code example demonstrates the IsHighSurrogate, IsLowSurrogate, and IsSurrogatePair methods.
' This example demonstrates the Char.IsLowSurrogate() method ' IsHighSurrogate() method ' IsSurrogatePair() method Imports System Imports Microsoft.VisualBasic 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 'Main End Class 'Sample ' '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 ' '---------------------------------------------------------------------- '
Available since 8
.NET Framework
Available since 2.0
Portable Class Library
Supported in: portable .NET platforms
Silverlight
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1