Random number

[Christo]

hello I am new to java very new and am hoping someone can offer me some
help.

I know that i need to use java.util.Random somewhere to generate a random
number

can anyone show me the code to do this very basic code to simply output the
random number that has been generated to the console?

I would really appreciate this, I can work from there to expand on what i
need ti to do

TIA

Christo

[Mark Rafn]

Christo <ch************@hotmail.comwrote:

>can anyone show me the code to do this very basic code to simply output the
random number that has been generated to the console?

public class RandomCoin {
/** flip a coin. */
public static void main(String[] args) {
java.util.Random rand = new java.util.Random();
System.out.println(rand.nextBoolean() ? "heads" : "tails");
}
}

Of course, if you prefer some other random type than boolean, call the
appropriate method - see the javadoc.

If you're using it for cryptography, you might prefer SecureRandom.
--
Mark Rafn da***@dagon.net <http://www.dagon.net/>

[j1mb0jay]

This will create you a random double.

//Creates random double.
double random = Math.random();

//Turns double into a number >=1
double Random = random * 10;

//Cast the double as an int (removes decimals)
int xOry = (int)Random;

--
Regards JJ (UWA)

"Christo" <ch************@hotmail.comwrote in message
news:L6******************************@bt.com...

hello I am new to java very new and am hoping someone can offer me some
help.

I know that i need to use java.util.Random somewhere to generate a random
number

can anyone show me the code to do this very basic code to simply output
the random number that has been generated to the console?

I would really appreciate this, I can work from there to expand on what i
need ti to do

TIA

Christo

[Ian Shef]

"j1mb0jay" <ja**@aber.ac.ukwrote in news:11***************@leri.aber.ac.uk:

This will create you a random double.

//Creates random double.
double random = Math.random();

//Turns double into a number >=1

No, because random may be a number less than 0.1
For example, 0.04382 * 10 becomes 0.4382

Perhaps you meant that this expands the range of the random number?

double Random = random * 10;

//Cast the double as an int (removes decimals)

....by truncation, may not be what you want. Consider Math.round().

int xOry = (int)Random;

There is some good information on generation of pseudorandom numbers in Java
at
http://mindprod.com/jgloss/pseudorandom.html

--
Ian Shef 805/F6 * These are my personal opinions
Raytheon Company * and not those of my employer.
PO Box 11337 *
Tucson, AZ 85734-1337 *

[j1mb0jay]

Sorry have only started messing with java when I started this course at
university, otherwise use to C#, was just trying to help, but if didn't know
it could return 0.0xxx I must edit code to allow for this mistake. Thanks
for the comment.

--
Regards JJ (UWA)

"Ian Shef" <in*****@avoiding.spamwrote in message
news:Xn****************************@138.126.254.21 0...

"j1mb0jay" <ja**@aber.ac.ukwrote in
news:11***************@leri.aber.ac.uk:

>This will create you a random double.

//Creates random double.
double random = Math.random();

//Turns double into a number >=1

No, because random may be a number less than 0.1
For example, 0.04382 * 10 becomes 0.4382

Perhaps you meant that this expands the range of the random number?

>double Random = random * 10;

//Cast the double as an int (removes decimals)

...by truncation, may not be what you want. Consider Math.round().

>int xOry = (int)Random;

There is some good information on generation of pseudorandom numbers in
Java
at
http://mindprod.com/jgloss/pseudorandom.html

--
Ian Shef 805/F6 * These are my personal opinions
Raytheon Company * and not those of my employer.
PO Box 11337 *
Tucson, AZ 85734-1337 *

[Rune Zedeler]

Ian Shef wrote:

...by truncation, may not be what you want.

Usually truncation is what you want. Round is normally never what you want.
For instance to throw a dice, use 1+(int)(Math.random()*6).

Math.round(Math.random()*10) gives 0 with 5% probability, 10 with 5%
probability and 1-9 with 10% probability each.

-Rune