Here's the best way to clone (deep copy) a object. Object can be type Array or Object.
/* [ xah_deep_copy_array_or_object(obj) deep copy/clone a object. This is the best way. fastest too. http://xahlee.info/js/js_clone_object.html Version 2017-01-30. ] */ const xah_deep_copy_array_or_object = ((obj) => JSON.parse(JSON.stringify(obj)));
For shallow copy, use the
slice method with no argument.
This is same as clone if your array does not contain elements that are references (that is, other array or objects.).
const oldArray = [3,4,5]; // shallow copy const newArray = oldArray.slice();
What's the Difference Between Deep Copy and Shallow Copy?
Shallow copy copies by reference of nested elements. This means, if you have shallow copy, changing a nested object may also change your copy.
// shallow copy isn't true clone const mm = ; const aa = [3,mm]; // shallow copy const bb = aa.slice(); mm = 4; // both are changed console.log(aa); // [ 3, [ 4 ] ] console.log(bb); // [ 3, [ 4 ] ]