1 using System; 2 3 public class Program 4 { 5 public static void Main() 6 { 7 object o ="3"; 8 int j = 4; 9 10 if(o is int i) 11 { 12 Console.WriteLine($"{i}x{j}={i*j}"); 13 } 14 else 15 { 16 Console.WriteLine("o is not an int so it cannot muitiply!"); 17 } 18 } 19 }