Binaryworld - GetPrimeNumbers - Evaluate the first N prime numbers ... [ VB -> Math ]

' Returns an array with the first N prime numbers
'
' Note: you can easily convert this routine to VB4 and VB5 by
' returning the result array through an argument instead of
' the return value

Function GetPrimeNumbers(numberOfPrimes As Long) As Long()
  Dim found As Long
  Dim n As Long
  Dim i As Long

  If numberOfPrimes <= 0 Then Err.Raise 1002, , "Invalid argument"

  ' we know the size of the result in advance
  ReDim result(1 To numberOfPrimes) As Long

  ' "2" is the first prime number
  result(1) = 2: found = 1

  n = 1
  Do
    ' all other prime numbers are odd, so we can skip even numbers
    n = n + 2
    ' let's check if N is a prime number
    For i = 1 To found
      If (n Mod result(i)) = 0 Then Exit For
    Next
    If i > found Then
      ' no prime number < N is a divisor for N
      ' therefore N is prime
      found = found + 1
      result(found) = n
      If found = numberOfPrimes Then Exit Do
    End If
  Loop

  GetPrimeNumbers = result
End Function