Check if a character is a Punctuation in CSharp

using System;  // w ww  .j a v  a2 s. c  o  m
  
class MainClass {     
  public static void Main() {     
    string str = "This is a test. $23"; 
    int i; 
 
    for(i=0; i < str.Length; i++) { 
      Console.Write(str[i] + " is"); 
      if(Char.IsPunctuation(str[i])) 
        Console.Write(" punctuation"); 
 
      Console.WriteLine(); 
    } 
  }
}