......n!

[chenko]

How do I use n! in VB? (eg 6! = 6 * 5 * 4 * 3 * 2 * 1 = 720)


Cheers!

[kedaman]

manual multiplication

r=1
For x=2 to n
  r=r*x
next x

[Good Dreams]

I think that a For ... Next block in a function is the only way.

Public Function Factorial(n as integer) 'the data type you want
factorial=1
for a=2 to n
factorial=factorial*a
next a
End Function

If there's an easier way, I would like to see it too.

[chenko]

Originally posted by Good Dreams
If there's an easier way, I would like to see it too.

yep there is, just sorted it

Function Factorial(N As Integer)
Factorial = 1
For X = 2 To N
Factorial = Factorial * X
Next X
End Function

Thanks!


Note: 500th post!!!!!

[kedaman]

Note: Simone learns
btw the inline solution is more efficient

[Good Dreams]

Originally posted by chenko

Note: 500th post!!!!!

[Illuminator]

defined recursively its like this:

function Fact (x) as long
  if x=0 then
    Fact = 1
  else
    Fact = x * Fact(x-1)
  end if
end function

[HarryW]

The dynamic programming algorithm is much more efficient in this case though, could save you a lot of function calls.

The only problem with using a long datatype is that it will only go up to 12! before it overflows. I'd suggest a double datatype, if you can sacrifice a little accuracy. If you need the range as well as the accuracy, then you could use a string implementation of a number of unlimited accuracy (well unless you run out of memory).

[chenko]

Originally posted by kedaman
Note: Simone learns

A whole load of notes you have there