prime numbers

[akaban]

hello i am trying to make a program for prime numbers but facing some problem can any one can help me in making this program

[SCBWV]

Good example using the Sieve of Eratosthenes algorithm - http://www.codeguru.com/columns/vb/article.php/c6575

[abu taher]

you didn't say what your problem. try this to check whether given number is a Prime Number

Option Explicit
 
Public Function IsPrime(ByVal n As Long) As Boolean
    Dim I As Long
    IsPrime = False
    If n <> 2 And (n And 1) = 0 Then Exit Function 'test if div 2
    If n <> 3 And n Mod 3 = 0 Then Exit Function 'test if div 3
    For I = 6 To Sqr(n) Step 6
        If n Mod (I - 1) = 0 Then Exit Function
        If n Mod (I + 1) = 0 Then Exit Function
    Next I
    IsPrime = True
End Function

[akaban]

thanks for your response dear but its showing compile error "invalid inside procedure"
sorry for incomplete description actually i need a program to print prime numbers from 1 to 100
i am working in vb6. and putting this coding in command button on click event, please check and reply.

actually i have made a program which is creating all of the non-prime numbers from 1 to 100 but i am unable to compare it... and generate prime numbers...

this is the program

Private Sub Command1_Click()
Dim o As Integer
Dim z As Integer
Dim y As Integer
Dim x As Integer
Dim W As Integer
Dim a(114) As Integer

 o = 0
 For z = 2 To 50
 o = o + 1
 a(o) = z * 2
 Next z
 
 For y = 2 To 33
 o = o + 1
 a(o) = y * 3
 Next y
 
 For x = 2 To 20
 o = o + 1
 a(o) = x * 5
 Next x
 
 For W = 2 To 14
 o = o + 1
 a(o) = W * 7
 Next W
 
 
End Sub

[WaltP]

Start by describing how you can tell if a number is prime.

[abu taher]

You can try this. in your code you use huge code.

[akaban]

Thanks abu tahir for your help