How to copy an array of arrays in JavaScript

The spread operator ... is useful to create a copy of a one-dimensional array:

javascript
let siblings = ['Erik', 'Andrea', 'Paula'];

let copy = [...siblings];

copy[0] = 'Erik Martín';

console.log(siblings); // ['Erik', 'Andrea', 'Paula']
console.log(copy); // ['Erik Martín', 'Andrea', 'Paula']

But it doesn't work using multidimensional arrays:

javascript
let siblings = [['Erik', 1990], ['Andrea', 1993], ['Paula', 2005]];

let copy = [...siblings];

copy[0][0] = 'Erik Martín';

console.log(siblings); // [['Erik Martín', 1990], ['Andrea', 1993], ['Paula', 2005]]
console.log(copy); // [['Erik Martín', 1990], ['Andrea', 1993], ['Paula', 2005]]

To do a deep copy of an array (if it's multidimensional), you can use a combination of JSON.parse() and JSON.stringify() functions:

javascript
let siblings = [['Erik', 1990], ['Andrea', 1993], ['Paula', 2005]];

let copy = JSON.parse(JSON.stringify(siblings));

copy[0][0] = 'Erik Martín';

console.log(siblings); // [['Erik', 1990], ['Andrea', 1993], ['Paula', 2005]]
console.log(copy); // [['Erik Martín', 1990], ['Andrea', 1993], ['Paula', 2005]]