CODEWITHSUNDEEP
vbaexcel
Adem
Adem

Reputation: 45

Random number creating

I got some help from one, and the code works perfectly fine.

What im looking for, is an explanation of the code, since my basic VBA-knowledge does not provide me with it.

Can someone explain what happens from "Function" and down?

Sub Opgave8()

For i = 2 To 18288
    If Left(Worksheets("arab").Cells(i, 12), 6) = "262015" Then
        Worksheets("arab").Cells(i, 3) = "18" & UniqueRandDigits(5)
    End If
Next i
End Sub
Function UniqueRandDigits(x As Long) As String
Dim i As Long
Dim n As Integer
Dim s As String
Do
n = Int(Rnd() * 10)
If InStr(s, n) = 0 Then
s = s & n
i = i + 1
End If
Loop Until i = x + 1

UniqueRandDigits = s
End Function

Upvotes: 0

Views: 85

Answers (2)

Ryszard Jędraszyk
Ryszard Jędraszyk

Reputation: 2412

The code loops from row 2 to 18288 in Worksheet "arab". If first 6 characters in 12th column are "262015", then in 3rd column macro will fill cell with value "18" followed by result of function UniqueRandDigits(5) which generates 5 unique digits (0-9).

About the UniqueRandDigits function, the most important is that Rnd() returns a value lesser than 1 but greater than or equal to zero.

Int returns integer value, so Int(Rnd() * 10) will generate a random integer number from 0 to 9.

If InStr(s, n) = 0 Then makes sure than generated integer value doesn't exist in already generated digits of this number, because as the function name says, they must be unique.

Upvotes: 1

Jean Rostan
Jean Rostan

Reputation: 1156

n = Int(Rnd()*10) returns a value between 0 and 9, since Rnd returns a value between 0 and 1 and Int converts it to an integer, aka, a natural number.

Then If InStr(s, n) = 0 checks if the random number is already in your result: if not, it adds it using the string concatenation operator &.

This process loops (do) until i = x + 1 where x is your input argument, so you get a string of length x. Then the first part just fills rows with these random strings.

N.B. : I explained using the logical order of the code. Your friend function UniqRandDigits is defined after the "business logic", but it's the root of the code.

Upvotes: 1

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