AppletTalk.com Java discussions newsgroups   Archives   FAQ   Search   Memberlist   Usergroups   Register   Profile   Log in to check your private messages   Log in  Random number          AppletTalk.com Forum Index -> comp.lang.java View previous topic :: View next topic   Author Message Christo Guest Posted: Wed Feb 07, 2007 6:03 am    Post subject: Random number 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 Back to top Mark Rafn Guest Posted: Wed Feb 07, 2007 8:10 am    Post subject: Re: Random number Christo <chris.me.white (AT) hotmail (DOT) com> wrote: Quote: 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 dagon (AT) dagon (DOT) net <http://www.dagon.net/> Back to top j1mb0jay Guest Posted: Thu Feb 08, 2007 4:18 am    Post subject: Re: Random number 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" <chris.me.white (AT) hotmail (DOT) com> wrote in message news:L6ydnbRgzPDCilTYnZ2dnUVZ8vednZ2d (AT) bt (DOT) com... Quote: 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 Back to top Ian Shef Guest Posted: Fri Feb 09, 2007 1:15 am    Post subject: Re: Random number "j1mb0jay" <jap6 (AT) aber (DOT) ac.uk> wrote in news:1170886729.974948 (AT) leri (DOT) aber.ac.uk: Quote: 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? Quote: double Random = random * 10; //Cast the double as an int (removes decimals) ....by truncation, may not be what you want. Consider Math.round(). Quote: 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 * Back to top j1mb0jay Guest Posted: Fri Feb 09, 2007 5:46 am    Post subject: Re: Random number 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" <invalid (AT) avoiding (DOT) spam> wrote in message news:Xns98D17CAFD9762vaj4088ianshef (AT) 138 (DOT) 126.254.210... Quote: "j1mb0jay" <jap6 (AT) aber (DOT) ac.uk> wrote in news:1170886729.974948 (AT) leri (DOT) 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 * Back to top Rune Zedeler Guest Posted: Sat Feb 10, 2007 5:58 am    Post subject: Re: Random number Ian Shef wrote: Quote: ...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 Back to top Display posts from previous: All Posts1 Day7 Days2 Weeks1 Month3 Months6 Months1 Year Oldest FirstNewest First         AppletTalk.com Forum Index -> comp.lang.java All times are GMT Page 1 of 1   Jump to: Select a forum Java Newsgroups----------------Java DiscussionsWeb-based java games comp.lang.java 3D Graphics API's for Java Java: Support and criticism Java System Announcements comp.lang.java.api JavaBeans Java and CORBA Java and Databases comp.lang.java.developer Java GUI Toolkits Java Help comp.lang.java.javascript JVM, native methods and hardware comp.lang.java.misc Java Language Programming Security and Java comp.lang.java.setup Java Software Tools comp.lang.java.tech ibm.software.java.linux  Non-English Java Newsgroups----------------Java Language (German)Language Java (Français)Java (Italian)  You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum Powered by phpBB © 2001, 2006 phpBB Group SEO toolkit © 2004-2006 webmedic.