Efficient get random whole number between two intervals

Question

I use this normally.

var min = 0;
var max = 1;

console.log(Math.round((Math.random() * (max - min) + min)));

It works fine and dandy, but I can't get over thinking that this may be an expensive way of producing this result, does anyone know of a more efficient way?

Or is this the most efficient way?

I don't know of any better ways, all implementations I've come across do the same — holtc, Apr 07 '15 at 13:24
This guy appears to be looking for the same thing, http://stackoverflow.com/questions/8775962/what-is-the-fastest-way-to-generate-a-random-integer-in-javascript — DasBeasto, Apr 07 '15 at 13:25
@DasBeasto Thanks man! This can be marked as duplicate is someone would please! — basickarl, Apr 07 '15 at 13:27

score 0 · Answer 1 · answered Apr 07 '15 at 13:26

0

Hey you can try this approach also

Math.floor(Math.random() * max) + min

This will work efficiently.

answered Apr 07 '15 at 13:26

Gaurav Mamidwar

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This isn't going to work. Your max here is a range – Chris Charles Apr 07 '15 at 13:34

score 0 · Answer 2 · answered Apr 07 '15 at 13:29

That's pretty much as efficient as it gets.

You could create a function which will at least clean up your code a bit:

Taken from https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/random

// Returns a random integer between min (included) and max (excluded)
// Using Math.round() will give you a non-uniform distribution!
function getRandomInt(min, max) {
  return Math.floor(Math.random() * (max - min)) + min;
}

Efficient get random whole number between two intervals

2 Answers2