copyWithin

Copies part of array within.

array.copyWithin(x, j, [i], [I]);
// x: an array
// j: write index
// i: read start index (0)
// I: read end index   (x.length)

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

var x = [1, 2, 3, 4, 5];
array.copyWithin(x, 3);
// [1, 2, 3, 1, 2]

array.copyWithin(x, 3, 1);
// [1, 2, 3, 2, 3]

array.copyWithin(x, 3, 1, 2);
// [1, 2, 3, 2, 5]

references

• Array.prototype.copyWithin(): MDN web docs
• immutable-array-prototype: @azu