run for random numbers and keep state [duplicate]

Answer 1

My solution uses Set to retain the uniqueness of the values:

const getRangeRandomizer = ([min, max]) => { // create the range randomizer
  const state = new Set(); // the numbers that were produced from the range
  
  /** the returned method can be used to get more numbers from the range **/
  return (numOfRandoms) => {
    const discarded = new Set(); // this Set is used to count numbers that are not unique
    const range = max - min + 1;
    const result = [];
    let i = 0;
    let randNum;

    while (i < numOfRandoms && discarded.size < range) { // if we added numOfRandoms times or we discarded delta optionsm the loop end - this prevents endless loops
      randNum = Math.floor(Math.random() * (range) + min);

      if (state.has(randNum)) {
        discarded.add(randNum);
      } else {
        state.add(randNum);
        result.push(randNum);
        i++;
      }
    }

    return result;
  }
}

const provideRanges = getRangeRandomizer([10, 20]); // create a range randomizer

console.log(provideRanges(4));
console.log(provideRanges(3));
console.log(provideRanges(2));
console.log(provideRanges(4)); // only 2 results will be provided, because the rest were used

const provideOtherRanges = getRangeRandomizer([15, 20]);  // create a range randomizer
console.log(provideOtherRanges(100));