Program to Generate Random Numbers in java?

There are following way to Generate Random Numbers in java.

Math.random() method :-

  • First we iterate the for loop from 0 to 4,then we multiply i value with Math.random() and return the double value.
  • Now add this double value to arrayList object
  • print this randomNum output.

DoubleStream doubles() method:-

  • Create the Random class Object with refernce random.
  • DoubleStream doubles() return a sequential stream of random numbers.

        java.util.Random.doubles(long streamSize, double randomNumberOrigin, double

        randomNumberBound)

import java.util.ArrayList;
import java.util.List;
import java.util.Random;
import java.util.stream.DoubleStream;

public class GenerateRandomNumber {
	public static void main(String[] args) {
		ArrayList<Double> randomNum = new ArrayList<Double>();
		for (int i = 0; i < 4; i++) {
			double value = i * Math.random();
			randomNum.add(value);
		}
		System.out.print("generate Random number using ArrayList :- " + randomNum);
        System.out.println();
        
		Random random = new Random();
		System.out.println("generate Random number using DoubleStream :-");
		DoubleStream doubleStream = random.doubles(4, 0, 1);

		doubleStream.forEach(System.out::println);
	}
}

Output :-
generate Random number using ArrayList :- [0.0, 0.9906354366238956, 0.7485715399071284, 0.618319353948994]
generate Random number using DoubleStream :-
0.9968514060329906
0.8460632293034756
0.43730908284083425
0.5183778936650153