Char.IsNumber Method (String, Int32)

Parameters

• s
  Type: System.String
  A string.

• index
  Type: System.Int32
  The character position in s.

Return Value

Type: System.Boolean
true if the character at position index in s is a number; otherwise, false.

Dim surrogate As String = ChrW(&hD800) + ChrW(&hDD07)     ' AEGEAN NUMBER ONE
For ctr As Integer = 0 To surrogate.Length - 1
   outputBlock.Text += String.Format("U+{0:X4} at position {1}: {2}",  
                     Convert.ToUInt16(surrogate(ctr)), ctr,  
                     Char.IsNumber(surrogate, ctr)) + vbCrLf
Next
' The example displays the following output:
'       U+D800 at position 0: True
'       U+DD07 at position 1: False

string surrogate = "\uD800\uDD07";         // AEGEAN NUMBER ONE
for (int ctr = 0; ctr < surrogate.Length; ctr++)
   outputBlock.Text += String.Format("U+{0:X4} at position {1}: {2}",
                     Convert.ToUInt16(surrogate[ctr]), ctr,
                     Char.IsNumber(surrogate, ctr)) + "\n";
// The example displays the following output:
//       U+D800 at position 0: True
//       U+DD07 at position 1: False

Module Example

   Public Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock)

      Dim str As String
      str = "non-numeric"

      outputBlock.Text &= Char.IsNumber("8"c) & vbCrLf      ' Output: "True"
      outputBlock.Text += String.Format(Char.IsNumber(str, 3)) & vbCrLf    ' Output: "False"

   End Sub

End Module

using System;

public class Example
{
   public static void Demo(System.Windows.Controls.TextBlock outputBlock)
   {
      string str = "non-numeric";

      outputBlock.Text += Char.IsNumber('8').ToString() + "\n";     
      outputBlock.Text += Char.IsNumber(str, 3).ToString() + "\n";
   }
}
// This example produces the following output:
//       True  
//       False