# Feature request: Array.prototype.random

I believe it's too specialized to be a part of Array interface.

Though, I think JS should have better support for randomness, so we could do:

prng.pick(arr); prng.sample(arr, 5); prng.sampleWithoutRepetitions(arr, 4);

On 15 Jun 2017 20:42, "Will White" <w.white9 at icloud.com> wrote:

Dear es-discuss,

I would like to propose Array.prototype.random, which would return a random
array element the same way `array[Math.floor(Math.random() * array.length)]`

does, because every time I want a random array element, I
have to remember how to do it. Do you think this is a useful addition to
the language?

Will White

And prng.pick(str), prng.pick(set) etc.?

Better idea: let's introduce an integer-based `Math.random`

equivalent
that can be optionally constrained to a specific range.

```
// Simple polyfill
Math.randomInt = Math.randomInt || function (start, end) {
if (arguments.length === 0) {
start = 0; end = Number.MAX_SAFE_INTEGER
} else if (arguments.length === 1) {
end = start; start = 0
}
start = Math.max(Math.floor(start), -Number.MAX_SAFE_INTEGER)
end = Math.min(Math.floor(end), Number.MAX_SAFE_INTEGER)
return Math.floor(Math.random() * (end - start)) + start
}
```

## You could then use it like this:
`array[Math.randomInt(array.length)]`

. I feel in this particular case,
a more general solution is much more useful than just a "pick some
random item in an array". (Number guessing games, anyone?)

Isiah Meadows me at isiahmeadows.com

Isaiah,

Better idea: let's introduce an integer-based

`Math.random`

equivalent that can be optionally constrained to a specific range.

There's a discussion of it here:

rwaldron/proposal-math-extensions#8

Peter

I agree that having a random integer function would be more suitable. Picking a random element from an array is a fairly uncommon thing but generating a random integer in a given range is something much more desirable.

2017-06-20 11:33 GMT+02:00 Isiah Meadows <isiahmeadows at gmail.com>:

Just putting in my $.02

I'm thinking math-rnd-util as an npm module would be a place to start... Then propose extending Math.rnd = rnd-util

Rnd.fill(array) Rnd.pick(array) Rnd.pick(min:int, max:int) ...

I suggest flushing things out in a usable npm module would be a good start.

Dear es-discuss,

I would like to propose Array.prototype.random, which would return a random array element the same way

`array[Math.floor(Math.random() * array.length)]`

does, because every time I want a random array element, I have to remember how to do it. Do you think this is a useful addition to the language?Will White