If a function fun() is to sometimes receive an int and sometimes a double then which of the following is the correct way of defining this function?

byte b1 = 0xAB;
byte b2 = 0x99;
byte temp;
temp = (byte)~b2;
Console.Write(temp + " ");
temp = (byte)(b1 << b2);
Console.Write (temp + " ");
temp = (byte) (b2 >> 2);
Console.WriteLine(temp);

int val;
for (val = -5; val <= 5; val++)
{
    switch (val)
    {
        case 0:
            Console.Write ("India"); 
            break;
    }
    
    if (val > 0)
        Console.Write ("B"); 
    else if (val < 0)
        Console.Write ("X");
}

< Serializable() > class sample
{ /* ... */ }

(Serializable()) class sample
{ /* ... */ }

[ Serializable() ] class sample
{ /* ... */ }

Serializablef) class sample
{ /* ... */ }