randomPermutation$ - nodef/extra-array GitHub Wiki

Pick an arbitrary permutation!

Alternatives: randomPermutation, randomPermutation$. Similar: randomPermutation, permutations, hasPermutation.

function randomPermutation$(x, n, fr)
// x:  an array (updated!)
// n:  number of values [-1 ⇒ any]
// fr: random number generator ([0, 1))

const xarray = require('extra-array');

var x = [1, 2, 3, 4, 5];
xarray.randomPermutation$(x, 5);
// → [ 2, 4, 5, 1, 3 ]

x;
// → [ 2, 4, 5, 1, 3 ]

var x = [1, 2, 3, 4, 5];
xarray.randomPermutation$(x, 5);
// → [ 5, 3, 1, 2, 4 ]

var x = [1, 2, 3, 4, 5];
xarray.randomPermutation$(x, 3);
// → [ 5, 3, 1 ]

References

• shuffle() : PHP
• Array.shuffle() : Sugar.js
• shuffle-seed : @webcaetano
• shuffle-array : @pazguille
• Seeding the random number generator in Javascript