How to Generate Random Integers Within a Specific Range in Java

const randomNumbersGenerator = () => {
  function getRandomInt(min, max) {
    min = Math.ceil(min);
    max = Math.floor(max);
    return Math.floor(Math.random() * (max - min) + min);
  }
  const randomNumber = () => getRandomInt(2, 12);
  const multiplierMap = new Map();
  const ranges = [[0, 2], [0, 3], [0, 3], [0, 3], [0, 3], [1, 4], [1, 4], [1, 4], [1, 4], [0, 2], [0, 3]];
  while(multiplierMap.size < 17) {
    for (let i = 2; i < ranges.length+1; i++) {
      const randomInt = randomNumber();
      if(Array.from(multiplierMap.values).includes(randomInt * i)){
        --i;
      } else {
        multiplierMap.set(randomInt + " " + i, randomInt * i);
      }
      if(multiplierMap.size === 18) break;
    }
  }
  console.log('MultiplierMap size: ', multiplierMap.size);
  for(let [pair, multiple] of multiplierMap){
    console.log('Generated Multiplier: ' + pair, '||', 'Generated * Multiplier: ' + multiple);
  }
  return multiplierMap;

};
randomNumbersGenerator();

Get random numbers in a specific range in java

Random rand = new Random(seed);
int random_integer = rand.nextInt(upperbound-lowerbound) + lowerbound;

Random Number generator in a range and then print length of the sequence

Consider using a while-loop:

import java.util.Random;

class Sequence {
    public static void main(String[] args) {
        Random r = new Random();
        int count = 0;
        int num = -1;
        System.out.println("The sequence is:");
        while (num != 0) {
            num = r.nextInt(10);
            System.out.print(num + " ");
            count++;
        }
        System.out.printf("%nThe length of the sequence is: %d%n", count);
    }
}

Example Output:

The sequence is:
3 9 3 9 4 0
The length of the sequence is: 6

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Alternatively if you need to store the sequence in a collection:

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

class Sequence {
    public static void main(String[] args) {
        Random r = new Random();
        List<Integer> result = new ArrayList<>();
        int num = -1;
        while (num != 0) {
            num = r.nextInt(10);
            result.add(num);
        }
        System.out.printf("The sequence is: %s%n", result);
        System.out.printf("The length of the sequence is: %d%n", result.size());
    }
}

How to generate random integers in a range

You could do

pepe = rng.nextInt(3) - 1;

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rng.nextInt(3) returns a random element in the set {0, 1, 2} - therefore subtracting 1 returns a random element in the set {-1, 0, 1}, as desired.

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Relevant documentation:

• nextInt

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