What is the Random.doubles method in Java?
Overview
doubles is an instance method of the Random class used to generate a stream of random double values. There are four different variants of the method:
doubles(long streamSize)doubles()doubles(long streamSize, double randomNumberOrigin, double randomNumberBound)doubles(double randomNumberOrigin, double randomNumberBound)
The Random class is defined in java.util package. To import the Random class, use the following import statement:
import java.util.Random;
doubles(long streamSize)
This method generates a stream of random double values of the specified size:
public DoubleStream doubles(long streamSize)
Parameters
long streamSize: The size of the stream.
Return value
The method returns a stream of random double values.
Code
import java.util.Random;public class Main{public static void main(String[] args) {//create an object of the Random classRandom random=new Random();// stream sizelong streamSize = 10;// using doubles generate stream of random doublesrandom.doubles(streamSize).forEach(System.out::println);}}
doubles()
This method generates an infinite stream of random double values.
public DoubleStream doubles()
Parameters
The method has no parameters.
Return value
The method returns a stream of random double values.
Code
import java.util.Random;public class Main{public static void main(String[] args) {//create an object of the Random classRandom random=new Random();// using doubles generate stream of random doublesrandom.doubles().limit(4).forEach(System.out::println);}}
doubles(long streamSize, double randomNumberOrigin, double randomNumberBound)
This method generates a stream of pseudorandom double values of the provided size, each adhering to the supplied origin (inclusive) and bound (exclusive).
public DoubleStream doubles(long streamSize, double randomNumberOrigin, double randomNumberBound)
Parameters
long streamSize: The size of the stream.double randomNumberOrigin: The origin of each value generated.double randomNumberBound: The bound of each value generated.
Return value
The method returns a stream of random double values.
Code
import java.util.Random;import java.util.stream.DoubleStream;public class Main{public static void main(String[] args) {//create an object of the Random classRandom random=new Random();// size of the streamint streamSize = 8;// origin of each random numberdouble randomNumberOrigin = 1.4;// bound of each random numberdouble randomNumberBound = 7.53;// Stream of random doubles generatedDoubleStream ds = random.doubles(streamSize, randomNumberOrigin, randomNumberBound);// print the generated random valuesds.forEach(System.out::println);}}
doubles(double randomNumberOrigin, double randomNumberBound)
This method generates an infinite stream of pseudorandom double values, each adhering to the supplied origin (inclusive) and bound (exclusive).
public DoubleStream doubles(double randomNumberOrigin, double randomNumberBound)
Parameters
double randomNumberOrigin: The origin of each value generated.double randomNumberBound: The bound of each value generated.
Return value
The method returns a stream of random double values.
Code
import java.util.Random;import java.util.stream.DoubleStream;public class Main{public static void main(String[] args) {//create an object of the Random classRandom random=new Random();// origin of each random numberdouble randomNumberOrigin = 1.42;// bound of each random numberdouble randomNumberBound = 7.23;// Stream of random doubles generatedDoubleStream ds = random.doubles(randomNumberOrigin, randomNumberBound);// print the generated random valuesds.limit(10).forEach(System.out::println);}}
