CODEWITHSUNDEEP
vb.netrandom
Null Spark
Null Spark

Reputation: 409

Why isn't the random number sequence the same?

I wrote this code below, expecting it to return the same thing each time I ran it, and it did not. May someone explain to me why A specifically seeded Random Number Generator would generate a different number each time I run it, because i wrote the same program as a command line application and it worked just fine.

Here is my VB.NET code (broken code):

'Bunch of WinForms Code
Private Sub PictureBox1_Click(ByVal sender As Object, ByVal e As EventArgs) Handles PictureBox1.Click
   Randomize(3)
   MsgBox(Rnd.ToString)
End Sub

Here is my working VB.NET Command Line Application:

Imports System.Console
Public Module rnum
    Sub Main()
        Randomize(3)
        WriteLine(Rnd.ToString) 'Returns 0.1387751
    End Sub
End Module

Upvotes: 3

Views: 129

Answers (1)

Charles May
Charles May

Reputation: 1763

What happens if you put the console code into a loop? I'm betting you would receive the same sequence of numbers. The console is running 1 time and producing the first result whereas if you click the button multiple times, you're in essence looping through the randomize results.

When I do this, 4 times I receive the same 4 numbers when I click the button 4 times.

Sub Main()
    For x As Integer = 0 To 3
        Randomize(3)
        Console.WriteLine(Rnd.ToString) 'Returns 0.1387751
    Next
    Console.ReadLine()
End Sub

produces:
0.1387751
0.05591547
0.8356526
0.2308619 

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
    Randomize(3)
    MsgBox(Rnd.ToString)
End Sub

produces
0.1387751 on 1st click
0.05591547 on 2nd click
0.8356526 on 3rd click
0.2308619 on 4th click

Upvotes: 4

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