Generate an Even random number

[martw]

What can I use to generate an Even random number please.

[RobDog888]

What you could do is generate a single dimensional array of random numbers. Then loop through the array using a For Next
loop but with a Step of 2.

Heres a link on Random

[martw]

Thanks RobDog, I didn't notice the thread was split before I posted again. I think that I got the Random() thing sussed.

[wossname]

Array??? what?

Just generate a normal random integer and multiply it by 2 to get an even number.

[martw]

Could anyone please explain the Math.Round function.

Dim RandomNo As Random = New Random
 
lblSomething.Text = Math.Round(RandomNo.Next(2, 12) * 2)

I want to know if that function affects the output generated. My guess is I'm just being noobish

[mendhak]

Math.Round Returns the number nearest the specified value.

[martw]

OK, thanks that helped. I guess I don't need it then

[martw]

With this code:

[COLOR=Red]Do Until (CInt(lblDiv1.Text) * 2) > lblDiv2.Text[/COLOR]
            lblDiv1.Text = Math.Round(RandomNo.Next(1, 24) * 2)
            lblDiv2.Text = Math.Round(RandomNo.Next(1, 24) * 2)
        Loop

I get this error:

An unhandled exception of type 'System.InvalidCastException' occurred in microsoft.visualbasic.dll

Additional information: Cast from string "" to type 'Integer' is not valid.

So what is wrong. I don't see a problem there... Does CInt only work when there is an integer already in lblDiv1?

[taxes]

Hi

You are trying to compare a numeric with a string and then put a numeric into a string. Use

Do Until (CInt(lblDiv1.Text) * 2) > CInt(lblDiv2.Text)
            lblDiv1.Text = Math.Round(RandomNo.Next(1, 24) * 2).ToString
            lblDiv2.Text = Math.Round(RandomNo.Next(1, 24) * 2).ToString
        Loop

[martw]

Doesn't work. Still shows the same error. the line I highlighted is where the program halts so I guess that is where the error is. I think it is happening because no integer is generated befor the CInt function is used, but thats me talking I will try something later, but in the meantime, I'm going to bed. Goodnight ;D

[mendhak]

Before that Do...Loop, check to see if the textbox is empty. Perform the operation only if the textbox is NOT empty.

[martw]

Wait, I'm going to sleep now. Thats what I was thinking. Which loop can I change it to so that it performs the check after the calculation? In Psuedocode that would be the REPEAT...UNTIL loop so what's the VB.nET equivalent?

[RobDog888]

Array??? what?

Just generate a normal random integer and multiply it by 2 to get an even number.

I should have realized that one. from the Prime number contest. Similar logic.
I seem to do things the hard way lately.

[Npath]

@martw

Try this:

If (lblDiv1.Text <> "") And (lblDiv2.Text <> "") Then
            Do Until (CInt(Val(lblDiv1.Text)) * 2) > CInt(Val(lblDiv2.Text))
                lblDiv1.Text = Math.Round(RandomNo.Next(1, 24) * 2).ToString
                lblDiv2.Text = Math.Round(RandomNo.Next(1, 24) * 2).ToString
            Loop
        Else
            MessageBox.Show("Textbox is empty")
        End If

I put the 'Val()' function in there just in case the user entered a non-numeric character.

Npath

[taxes]

Hi martw,

You were testing the code suggestion by putting a non-numeric in the textbox????????????

[martw]

Oh, crack! I forgot to mention that this code is in the FormLoad event. Sorry. It is meant to generate a random number which the user will use after a timer event enabls an object on the form. Sorry Npath, but thanks for going through that. So basically, the nubers are generated on Form_Load and thats it. So thats why I guess I need to generate the numbers before they are checked. So back to my previous question, what is the the equivalent loop in VB.NET to REPEAT...UNTIL in psuedocode? Thanks.

[SuperSparks]

Do Until [condition is true]
' do stuff here
Loop
 
 
or
 
Do While [condition is false]
' do stuff here
Loop

[martw]

The Do Loop still checks the condition before the action is exceuted. I want it to do this:

REPEAT
[This Action]
UNTIL [Condition is true]

You showed me:

WHILE [Condition is False/True]
[This Action]
END WHILE

[Npath]

@martw,

I am also used to 'Repeat Until' loops (I just started using VB.NET). Luckily, VB.NET has this:

Dim UserInput As String
        Do
            Console.WriteLine("Enter q to quit")
            UserInput = Console.ReadLine()
        Loop Until UserInput = "q"

Npath

[martw]

Wha? Its that easy? Thats emabarrassing... Thanks Npath

[Npath]

You're welcome...