Generate Unique Numbers in Array

Question

I\'m new to javascript and trying to get comfy with Functions, For loops, and If statements. I\'m working on a simple exercise that genera

Answer 1

There are many ways to solve this problem. I am contributing my way of solving it.

function randoNumbers(min, max) {

  let randomNumbers = [];

  for (; randomNumbers.length < 5;) {
    const value = Math.floor(Math.random() * (max - min) + +min);
    if (!randomNumbers.includes(value))
      randomNumbers.push(value);
  }
  console.log(randomNumbers);

}



randoNumbers(1, 10);

Answer 2

A very plain solution would be to generate numbers until the generated number is not already included in the array, and then push it to the result array:

function randoNumbers(min, max) {
  const randomNumbers = [];
  for (let counter = 0; counter < 5; counter++) {
    let num;
    do {
      num = Math.floor(Math.random() * (max - min) + min);
    }
    while (randomNumbers.includes(num))
    randomNumbers.push(num);
  }
  console.log(randomNumbers);
}

randoNumbers(1, 10);

For slightly better complexity, you could use a Set instead (set.has is quicker than arr.includes):

function randoNumbers(min, max) {
  const set = new Set();
  for (let counter = 0; counter < 5; counter++) {
    let num;
    do {
      num = Math.floor(Math.random() * (max - min) + min);
    }
    while (set.has(num))
    set.add(num);
  }
  console.log([...set]);
}

randoNumbers(1, 10);