Selecting random array elements and placing into another

Question

I have an array of strings and require just 4 of these (randomly) to be placed into another array.

var a = ["Orange", "Red", "Yellow", "Blue", "Black", "White", "Brown", "Green"];
var b = [];
function selectColours(){
    var toRandomise = a[Math.floor(Math.random() * 4)];
    b.push(toRandomise);
}
console.log(b);

My problem is that the Console shows nothing appearing.

This way you can't get any further than "Blue". Replace a[Math.floor(Math.random() * 4)]with a[Math.floor(Math.random() * a.length)] — Redu
– Redu, Commented May 13, 2016 at 14:07

GMchris · Accepted Answer · 2016-05-13 12:30:45Z

3

Well, you're not really running the function you created. Simply declaring it.

Just write selectColors(); right before the console.log

answered May 13, 2016 at 12:30

GMchris

5,7064 gold badges25 silver badges40 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

Artificial Crayon Over a year ago

Doing this only shows one random string, not the 4 that I require to e stored in the array.

GMchris Over a year ago

If you want four strings, rather than one you should put it in a loop. Right now you're just getting a random number between 0 and 3. Also note, that if you don't want results to be duplicated (Having two "Red"s for instance) you need to remove the elements.

Artificial Crayon Over a year ago

I see where I am going wrong now and a loop has solved it, thankyou.

Nenad Vracar · Accepted Answer · 2016-05-13 12:46:38Z

2

You also need add random value 4 times so you can use for loop

var a = ["Orange", "Red", "Yellow", "Blue", "Black", "White", "Brown", "Green"];
var b = [];

function selectColours() {
  for (var i = 0; i < 4; i++) {
    var toRandomise = a[Math.floor(Math.random() * 4)];
    b.push(toRandomise);
  }
}

selectColours()
console.log(b);

You can also use recursion.

var a = ["Orange", "Red", "Yellow", "Blue", "Black", "White", "Brown", "Green"];
var b = [], count = 0;


function selectColours() {
  if (count == 4) return true;
  b.push(a[Math.floor(Math.random() * 4)]);
  count++;
  selectColours();
}

selectColours()
console.log(b);

edited May 13, 2016 at 12:46

answered May 13, 2016 at 12:34

Nenad Vracar

122k16 gold badges160 silver badges184 bronze badges

Collectives™ on Stack Overflow

Selecting random array elements and placing into another

2 Answers 2

3 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

3 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related