# Generate Random Doubles in an Array in Java

Shiv Yadav Jan 30, 2023 Dec 30, 2021

This article will introduce how to generate random doubles in a Java array.

## Generate Random `double` in a Java Array Using the `java.util.Random` Class

In Java, we utilize the `nextDouble()` method of the `java.util.Random` class to generate a random array of doubles. This function returns the next random double value generated by this random number generator.

Example:

``````import java.util.Random;
public class RandomDoubles
{
public static void main(String[] args)
{
Random rd = new Random();
double[] array = new double;
for (int i = 0; i < array.length; i++)
{
array[i] = rd.nextDouble();
System.out.println(array[i]);
}
}
}
``````

Here, `rd.nextDouble()` returns a number between 0 and 1.0.

Output:

``````0.6281807590035252
0.34456583017282394
0.23684352236085848
``````

### Shorter Version

There is a shorter version of doing the same thing as the following.

Example:

``````import java.util.Random;
public class RandomDoubles
{
public static void main(String[] args)
{
Random rd = new Random();
double[] array = rd.doubles(5,10,100).toArray();
}
}
``````

Th first argument of `rd.doubles` method takes the number of random doubles you want in the array. And, the second and third argument takes a minimum and maximum value of range for generating random numbers.

Output:

``````78.21950288465801
80.12875947698258
94.95442635507693
88.63415507060164
31.283712117527568
``````

## Generate Random `double` in a Java Array Using `ThreadLocalRandom`

We can also generate random doubles by using `ThreadLocalRandom`.

Example:

``````import java.util.concurrent.ThreadLocalRandom;
public class RandomDoubles
{
public static void main(String[] args)
{
for(double num: randoms){
System.out.println(num);
}
}
}
``````

Output:

``````0.5417255613845797
0.2522145088132569
0.42238415650855565
0.8432309480218088
0.13192651019478996
``````