static void Main(string[] args)
{
projectclass pc = new projectclass();
pc.display1();
pc.display2();
int a = pc.display3(2, 5);
Console.WriteLine(a);
pc.display4();
}
public static int display3(this projectclass pc, int a, int b)
{
return(a * b);
}
public static void display4(this projectclass pcc)
{
Console.WriteLine(pcc);
}