random number gene betwn 2 no's

[Mahesh Pinnamaneni]

hai dudes,
i need to generate random numbers(ofcourse using Math.random()) between the 2 numbers only(say i need to generate no's betwn 1 and 50 only).how can we achieve this.

thankQ
Bye
Mahesh

[somkiat puisungnoen]

I think , java.util.Random class is easy to use more than java.lang.Math.random() method...


So, if you want to random number between 2 number.

Example random 1 - 50

 
import java.util.Random;
 
/**
 * @author somkiat.p
 *
 * TODO To change the template for this generated type comment go to
 * Window - Preferences - Java - Code Generation - Code and Comments
 */
public class TestRandom {
 
public static void main(String[] args) {
Random r = new Random();
int no= 0;
                //Check result between 1 to 50
while(no < 1) {
no = r.nextInt(50);
}

System.out.println("Random Number : " + no);

}
}
 

[Ko Ko Naing]

Originally posted by Somkiat Puisungnoen:

 
import java.util.Random;
 
/**
 * @author somkiat.p
 *
 * TODO To change the template for this generated type comment go to
 * Window - Preferences - Java - Code Generation - Code and Comments
 */
public class TestRandom {
 
public static void main(String[] args) {
Random r = new Random();
int no= 0;
                //Check result between 1 to 50
while(no < 1) {
no = r.nextInt(50);
}

System.out.println("Random Number : " + no);

}
}
 

Mmm, Pui, I guess you forgot to have a look at the API that the parameter is exclusive.. So 50 won't be included in the randomized numbers... Instead of no = r.nextInt(50);, it should be no = r.nextInt(51); so that 50 is included in the randomized numbers...

Am I a bug fixer? :roll: Anyway, I hope the original poster gets what he wants correctly...

[somkiat puisungnoen]

Thank you for your comment....

[Mahesh Pinnamaneni]

Dear Friends,
Thanks alot for ur ans but i hope the ans u have provided is not satisfactory , becoz i need to generate random numbers between 2 numbers i.e say betwn 10 and 50 or 50 and 100 etc and not just 0 and 10,50 etc.
the solution u have given is only for numbers betwn 0 and 20,30 likewise .
Hope u got my Q
regards,
Mahesh

[Nick George]

look into the '+' operator, when applied to int,int

[Tony Morris]

http://www.xdweb.net/~dibblego/java/faq/answers.html#q13
[ September 07, 2004: Message edited by: Tony Morris ]

[Max Rahder]

Just use Random#nextInt(int), for example:

Random r = new Random();
// Calculate a random integer between low (inclusive) and high (exclusive).
int low = 1;
int high = 50;
int i = r.nextInt(high-low);
int result = i + low;

Note that there are issues relating to initial seed values when creating a random number generator. You should read the API documentation for details.

[fred rosenberger]

you need to figure out the range of possible values. if i want a number between 1 and 10, inclusive on both ends, there are 10. between 8 and 24 (inclusive) - 17.

generate a random integer that is less than the range. so in my second example, i would try to make a random number between 0 and 16 inclusive.

then, you need to figure out the offset. in my second example, my offset is 8. so, add 8 to my generated number.