What is clone?
The clone npm package is a utility for cloning JavaScript objects. It can create deep copies of objects, arrays, dates, and other types, ensuring that changes to the cloned object do not affect the original. It is useful when you need to work with copies of data without altering the original source.
What are clone's main functionalities?
Cloning objects
This feature allows you to create a deep copy of an object, so that changes to the cloned object do not affect the original object.
{"const clone = require('clone');
const obj = { a: 1, b: { c: 2 } };
const objClone = clone(obj);
console.log(objClone); // { a: 1, b: { c: 2 } }
objClone.b.c = 3;
console.log(obj.b.c); // 2, original object is not affected"}
Cloning arrays
This feature allows you to create a deep copy of an array, including any nested arrays, without affecting the original array.
{"const clone = require('clone');
const arr = [1, 2, [3, 4]];
const arrClone = clone(arr);
console.log(arrClone); // [1, 2, [3, 4]]
arrClone[2][0] = 5;
console.log(arr[2][0]); // 3, original array is not affected"}
Cloning dates
This feature allows you to clone Date objects, creating a new instance that represents the same moment in time as the original.
{"const clone = require('clone');
const date = new Date();
const dateClone = clone(date);
console.log(dateClone); // date object representing the same moment in time
console.log(date === dateClone); // false, they are different instances"}
Other packages similar to clone
lodash.clonedeep
lodash.clonedeep is a method from the Lodash library that provides deep cloning of objects and arrays. It is similar to clone but is part of a larger utility library that offers a wide range of functions for manipulating and traversing data.
deep-copy
deep-copy is another npm package that offers deep cloning functionality. It supports cloning of complex objects, including those with circular references. It is similar to clone but also handles functions and symbols, which clone does not.
rfdc
rfdc (Really Fast Deep Clone) is a package that focuses on performance for deep cloning objects and arrays. It claims to be faster than other deep cloning methods, especially for large objects. Unlike clone, rfdc does not support cloning of functions, dates, regexes, maps, sets, blobs, filelists, image data, or array buffers.
clone
offers foolproof deep cloning of variables in JavaScript.
Installation
npm install clone
Example
var clone = require('clone');
var a, b;
a = { foo: { bar: 'baz' } };
b = clone(a);
a.foo.bar = 'foo';
console.log(b);
This will print:
{ foo: { bar: 'baz' } }
clone masters cloning simple objects (even with custom prototype), arrays,
Date objects, and RegEx objects. Everything is cloned recursively, so that you
can clone dates in arrays in objects, for example.
API
clone(obj, circular)
Call clone
with circular
set to false
if you are certain that obj
contains no circular references. This will give better performance if needed.
There is no error if undefined
or null
is passed as obj
.
Circular References
var a, b;
a = { hello: 'world' };
a.myself = a;
b = clone(a);
console.log(b);
This will print:
{ hello: "world", myself: [Circular] }
So, b.myself
points to b
, not a
. Neat!
Bugs and Issues
If you encounter any bugs or issues, feel free to open an issue at
github.
License
Copyright © 2011-2012 Paul Vorbach
Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the “Software”), to deal in
the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
the Software, and to permit persons to whom the Software is furnished to do so,
subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, OUT OF OR IN CONNECTION WITH THE
SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.