Need VBA code to display 1st PRIME number greater than value (N)

[cramer2828]

find the first PRIME number greater than a given number N. So for example, if N is 10 it should return 11, and if N is 24 it should return 29 (since 25-28 are not prime numbers.)

Any help would be much appreciated, I'm not even sure where to start. Thank you.

[EirikDaude]

I'd start with doing something like this.

[GTO]

Hi Erik,

I did not check any of the hits, but just had to comment... Tears, can't see, too funny!!!

Mark

[Paul_Hossler]

Is this for developing an algorithm (e.g. homework)? Is there a upper limit?

Otherwise, the fastest way would be be to just load a list of the first 10,000 or so numbers and use =MATCH()

[JKwan]

using what Erik posted (too funny), this is what I came up

Private Function IsDecimal(Number) As Boolean
    Dim splitted() As String
    splitted = Split(Number, ".")
    If UBound(splitted) <> 0 Then
        IsDecimal = True
    End If
End Function
Private Function IsPrimeNumber(Number) As Boolean
    For i = 2 To Number - 1
        If IsDecimal(Number / i) = False Then
            IsPrimeNumber = False
            Exit Function
        End If
    Next i
    IsPrimeNumber = True
End Function
Public Function NextPrime(Number As Long) As Long
    Dim lCheckPrimeNumber As Long
    Dim bPrime As Boolean
    
    lCheckPrimeNumber = Number
    Do
        lCheckPrimeNumber = lCheckPrimeNumber + 1
        bPrime = IsPrimeNumber(lCheckPrimeNumber)
        If bPrime Then
            NextPrime = lCheckPrimeNumber
        End If
    Loop While Not bPrime
End Function