array-copyWithin Polyfill for Array.prototype.copyWithin. Usage Functionally: var copyWithin = require('array-copywithin'); var array = copyWithin([1, 2, 3, 4, 5], 0, 3); console.log(array);// => [4, 5, 3, 4, 5] From Array object: require('array-copywithin/shim'); var array = [1, 2, 3, 4, 5].copyWithin(0, 3); console.log(array);// => [4, 5, 3, 4, 5] License MIT © Shogo Sensui