public static void Main()
Console.WriteLine("Hello World");
Console.WriteLine(textt);
Console.WriteLine("bbb" + textt.Replace("H","M"));
Console.WriteLine(textt);
String str = "Geeks For Geeks";
Console.WriteLine("OldString : " + str);
Console.WriteLine("NewString: " + str.Replace("s", "G"));
Console.WriteLine("\nOldString: " + str);
Console.WriteLine("NewString: " + str.Replace('e', ' '));