Char.IsSurrogatePair Method (Char, Char)

Parameters

• highSurrogate
  Type: System.Char
  A character.

• lowSurrogate
  Type: System.Char
  A character.

Return Value

Type: System.Boolean
true 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.

' This example demonstrates the Char.IsSurrogatePair() method

Class Example
   Public Shared Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock)
      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(vbCrLf, _
                                              New [String]("-"c, 70), _
                                              vbCrLf)

      outputBlock.Text &= vbCrLf
      outputBlock.Text &= String.Format("Hexadecimal code point of the character, cHigh: {0:X4}", AscW(cHigh)) & vbCrLf
      outputBlock.Text &= String.Format("Hexadecimal code point of the character, cLow:  {0:X4}", AscW(cLow)) & vbCrLf
      outputBlock.Text &= vbCrLf
      outputBlock.Text &= String.Format("Characters in string, s1: 'a', high surrogate, low surrogate, 'z'") & vbCrLf
      outputBlock.Text &= String.Format("Hexadecimal code points of the characters in string, s1: ") & vbCrLf
      Dim i As Integer
      For i = 0 To s1.Length - 1
         outputBlock.Text &= String.Format("s1({0}) = {1:X4} ", i, AscW(s1.Chars(i))) & vbCrLf
      Next i
      outputBlock.Text &= divider & vbCrLf

      outputBlock.Text &= "Is each of the following pairs of characters a surrogate pair?" & vbCrLf
      outputBlock.Text &= String.Format("C1) cHigh and cLow?  - {0}", [Char].IsSurrogatePair(cHigh, cLow)) & vbCrLf
      outputBlock.Text &= String.Format("C2) s1(0) and s1(1)? - {0}", [Char].IsSurrogatePair(s1, 0)) & vbCrLf
      outputBlock.Text &= String.Format("C3) s1(1) and s1(2)? - {0}", [Char].IsSurrogatePair(s1, 1)) & vbCrLf
      outputBlock.Text &= String.Format("C4) s1(2) and s1(3)? - {0}", [Char].IsSurrogatePair(s1, 2)) & vbCrLf
      outputBlock.Text &= divider & vbCrLf
   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 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.IsSurrogatePair() method
using System;

class Example
{
   public static void Demo(System.Windows.Controls.TextBlock outputBlock)
   {
      char cHigh = '\uD800';
      char cLow = '\uDC00';
      string s1 = new String(new char[] { 'a', '\uD800', '\uDC00', 'z' });
      string divider = String.Concat("\n", new String('-', 70),
                                      "\n");

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

      outputBlock.Text += "Is each of the following pairs of characters a surrogate pair?" + "\n";
      outputBlock.Text += String.Format("C1) cHigh and cLow?  - {0}", Char.IsSurrogatePair(cHigh, cLow)) + "\n";
      outputBlock.Text += String.Format("C2) s1[0] and s1[1]? - {0}", Char.IsSurrogatePair(s1, 0)) + "\n";
      outputBlock.Text += String.Format("C3) s1[1] and s1[2]? - {0}", Char.IsSurrogatePair(s1, 1)) + "\n";
      outputBlock.Text += String.Format("C4) s1[2] and s1[3]? - {0}", Char.IsSurrogatePair(s1, 2)) + "\n";
      outputBlock.Text += divider + "\n";
   }
}
/*
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 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

----------------------------------------------------------------------
*/