Random numbers between number range in Java

[prileep]

if i use java.util.Random i can create random numbers.

But how do i can define a Random object that its methods like
nextInt() should return between two specified numbers(Eg: i want to create random numbers between 100 and 200)

[r035198x]

if i use java.util.Random i can create random numbers.

But how do i can define a Random object that its methods like
nextInt() should return between two specified numbers(Eg: i want to create random numbers between 100 and 200)

Math.random() will do the job for you there.

 int x = 100 + (int)(Math.random()*200);

[prileep]

Ok i got the result with ur solnution. But i wanted to know whether i can set a random object to return value between a specified lower limit and upper limit so that i need not to worry about the complexity of calculations

[r035198x]

Ok i got the result with ur solnution. But i wanted to know whether i can set a random object to return value between a specified lower limit and upper limit so that i need not to worry about the complexity of calculations

You would have to write your own custom method for it.
Something like

 public int nextInt(Random r, int lower, int higher) { 
    int ran = r.nextInt();
    double x = (double)ran/Integer.MAX_VALUE * higher;
    return (int)x + lower;
 }
 

[r035198x]

You would have to write your own custom method for it.
Something like

 public int nextInt(Random r, int lower, int higher) { 
    int ran = r.nextInt();
    double x = (double)ran/Integer.MAX_VALUE * higher;
    return (int)x + lower;
}
 

This will return values from lower to higher + lower so you will need to scale it again

[prileep]

I got the soltion from custom method.
Thanks for giving the better solution.

[horace1]

Ok i got the result with ur solnution. But i wanted to know whether i can set a random object to return value between a specified lower limit and upper limit so that i need not to worry about the complexity of calculations

another alternative

  Random r=new Random();
   int n=(r.nextInt(101) + 100);
 

r.nextInt(101) returns a value between 0 and 100 and you then add 100

[Vladimir1]

if i use java.util.Random i can create random numbers.

But how do i can define a Random object that its methods like
nextInt() should return between two specified numbers(Eg: i want to create random numbers between 100 and 200)

Hello, friend,
Try the following, plz:

public class Ex {
public static void main(String[] args) {
System.out.println(Math.round(Math.random()*100+10 0));
}
}

Vladimir1

[jfivekiller]

if i use java.util.Random i can create random numbers.

But how do i can define a Random object that its methods like
nextInt() should return between two specified numbers(Eg: i want to create random numbers between 100 and 200)

Here was my simple solution to random numbers in a range

import java.util.Random;
public class Random2 extends Random{

public int nextInt(int lower,int upper){
return nextInt((upper-lower+1))+lower;

}
}

[JosAH]

You would have to write your own custom method for it.
Something like

 public int nextInt(Random r, int lower, int higher) { 
    int ran = r.nextInt();
    double x = (double)ran/Integer.MAX_VALUE * higher;
    return (int)x + lower;
 }
 

Bzzzt! Thanks for playing; close but no cigar ;-)

Better make that line:

    double x = (double)ran/Integer.MAX_VALUE * (higher-lower);
 

Using "nextInt(higer-lower)+lower" is also an option.

kind regards,

Jos

kind regards,

Jos

[r035198x]

Bzzzt! Thanks for playing; close but no cigar ;-)

Better make that line:

    double x = (double)ran/Integer.MAX_VALUE * (higher-lower);
 

Using "nextInt(higer-lower)+lower" is also an option.

kind regards,

Jos

kind regards,

Jos

Did I do that?

Thanks for digging up this thread guys. Otherwise my mistake would not have been noticed.

[JosAH]

Did I do that?

Thanks for digging up this thread guys. Otherwise my mistake would not have been noticed.

I didn't dig up anything; I'm innocent as always; fivekiller found it; good work ;-)

kind regards,

Jos

[sajib99]

@r035198x
This should be the following:

 int x = 100 + (int)(Math.random()*100);

[Ungihan]

import java.util.Random;
public class Question {
 
 
    public static void main(String[] args) {
      Random random = new Random ();
         int x = 100 + (int)(Math.random()*200);
            System.out.println(Math.round(Math.random()*200));
    }
 
}