Generate a random boolean

Question

I am a little stuck with a simple Question: how to generate a simple random Boolean?
If am correct, a Boolean 0 = false and 1 = true, but how to suse that?

Current code:

Dim RandGen As New Random
Dim RandBool As Boolean
RandBool = Boolean.Parse(RandGen.Next(0, 1).tostring)

Generate a random number, multiply it by 2 and round down? `CInt(Math.Floor(Rnd() * 2))` should produce 0 or 1 which you could then use — dudledok, Mar 10 '13 at 17:38
Also, see this previously asked question: [Random Int in VB.Net](http://stackoverflow.com/questions/18676/random-int-in-vb-net) — Paul J Hurtado, Mar 10 '13 at 20:07
Dudledok it does work - but how does it work? Especially the multiplication with two is surprising for me. — Christian Sauer, Mar 11 '13 at 07:48

Caramiriel · Accepted Answer · 2013-03-15T11:22:28.677

23

Or just simply:

Random rng = new Random();
bool randomBool = rng.Next(0, 2) > 0;

Saves some processing power of parsing text, whereas a simple compare is enough.

Edit: Second parameter is exclusive, so should be .Next(0, 2).

edited Mar 15 '13 at 11:22

answered Mar 10 '13 at 18:00

Caramiriel

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That is neat, I will go with it, thanks. How does it work? Does it round the resultung random number to 0 / 1 and then tests if the value is greater than 0? – Christian Sauer Mar 11 '13 at 07:47
It generates either an integer 0 or 1. This number is checked if it is larger than zero. If it is, then it returns `true`, otherwise `false`. It's actually just in inline if-statement. Since the actual number generator already generates a 50% chance of being zero or one, it just need to be mapped from `[0,1]` to `[false,true]`. – Caramiriel Mar 11 '13 at 07:54
The first parameter of 0 is optional because that is the default. `rng.Next(2) > 0` is sufficient. – wensveen Dec 19 '18 at 11:45

score 1 · Answer 2 · answered Jul 09 '13 at 17:24

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Dim RandGen As New Random

    Dim RandBool As Boolean

    RandBool = RandGen.Next(0, 2).ToString

    TextBox1.Text = RandBool

answered Jul 09 '13 at 17:24

Technikminer

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Does that mean that we can assign a string value to a variable of type Booelan, in VB.NET? – user1451111 Jul 05 '18 at 14:28

Christian Lennartsson · Answer 3 · 2013-03-10T18:15:37.560

0

Maybe something like this?

        string[] trueOrFalse = { "false", "true"};
        bool RandBool = bool.Parse(trueOrFalse[RandGen.Next(0,2)]);

edited Mar 10 '13 at 18:15

answered Mar 10 '13 at 17:55

Christian Lennartsson

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Good idea, but why declare your array as a string array instead of a boolean array? You have one extra not necessary step. – Meta-Knight Mar 10 '13 at 20:33

Generate a random boolean

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