Math.random() call number only one time

Question

So as my question is how to call random number, but only 10 times (when we got numbers from 0 to 9) with different numbers. here is code for generate random number:

Math.floor(Math.random() * 10);

but that code for example can get number 2, two times.

example output: 4, 3, 2, 9, 4, 3, 6, 3;

How to get output like that: 5, 3, 6, 4, 1, 9, 8, 2;

Here is a function:fiddle: but, numbers are random and can repeat and going over and over.

So how to replace number when number already exist, and stop variable from calling when all numbers was used?!

https://stackoverflow.com/questions/2380019/generate-unique-random-numbers-between-1-and-100 — AussieJoe, Mar 28 '18 at 20:10
this may help. https://stackoverflow.com/questions/40056297/random-number-which-is-not-equal-to-the-previous-number — Nina Scholz, Mar 28 '18 at 20:17
see also: https://stackoverflow.com/questions/6274339/how-can-i-shuffle-an-array — JonSG, Mar 28 '18 at 20:17

score 2 · Answer 1 · answered Mar 28 '18 at 20:13

2

Sounds to me like you don't really want a series of random numbers, you want to randomly shuffle a series of non-random numbers. Here's how I'd do it:

var nums = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9];
for(var i = nums.length; i > 0; i--) {
    var temp = nums[i - 1];
    var swapIndex = Math.floor(Math.random() * i);
    nums[i - 1] = nums[swapIndex];
    nums[swapIndex] = temp;
}

answered Mar 28 '18 at 20:13

EKW

2,059
14
24

I have 23 divs. And I need to animated them 1 by one only 1 time becouse they are going in to 3d perspectove. But thanks anyway. – Piotr Mirosz Mar 28 '18 at 20:21
@PiotrMirosz This is the answer you seek. What (if anything) is not working for you? – JonSG Mar 28 '18 at 20:24
i think i'm not able to use your answer. Not working for me, but maybe will work for someone. – Piotr Mirosz Mar 28 '18 at 20:38
i going to make another question, i'm not going to change that one when answers was correct. – Piotr Mirosz Mar 28 '18 at 20:44

S.Davis · Answer 2 · 2018-03-28T20:22:22.287

2

You could try something like this

var limit = 10;
var results = []

function randomGenerator () {
    while (results.length < (limit -1)) {
      var generated = Math.ceil(Math.random() * limit);
      if (results.indexOf(generated) < 0) {
          results.push(generated)
      }
  }
}

randomGenerator()
alert(results)

edited Mar 28 '18 at 20:22

answered Mar 28 '18 at 20:13

S.Davis

96
5

Goes into infinite loop. – Tripp Kinetics Mar 28 '18 at 20:18
No it doesn't https://jsfiddle.net/Lq4v4s1L/6/ – S.Davis Mar 28 '18 at 20:20

Math.random() call number only one time

2 Answers2