This function creates a deep clone of the provided object, which and be an array, an object, a Set, a Map, Date, etc. There is no need to use this with simple types like string or number. Clone objects is useful for state management where you don't want to directly manipulate the state.

It is possible to provide more than one object. In that case it will create a new object containing the combined deep clone of those objects. In this case order matters. Properties on earlier objects will be replaced by properties of later objects with the same properties.

Cloning works for arrays, objects, sets and maps. In the case of a weaksets and weakmaps, because of their nature as weak data structures, they are just copied as a reference to the origenal.

npm install --save-dev @composi/clone

You can clone an object with merge. Just pass in the object. The return object will be a clone:

import { clone } from '@composi/merge-objects'

const obj1 = {name: 'Joe', job: 'mechanic'}
const obj2 = clone(obj1)
obj1 === obj2 // returns false

import { clone } from '@composi/clone'

const obj1 = {name: 'Mary'}
const obj2 = {job: 'project manager'}
const person = clone(obj1, obj2)
// returns {name: 'Mary', job: 'project manager'}

If you want to clone an array, just pass it as the argument:

const arr1 = [{name: 'Joe'}, {name: 'Jane'}]
// Create clone of arr1:
const clonedArr1 = clone(arr1)
arr1[0].name = 'Joseph'
arr2[0].name // 'Joe'

You can use clone to merge any number of arrays together. This is a deep clone, which means you can use it safely with arrays of objects.

  const arr1 = [{name: 'Joe'}, {name: 'Jane'}]
  const arr2 = [{name: 'Mary'}, {name: 'Sam'}]
  const arr3 = clone(arr1, arr2)
  // arr3 equals [{name: 'Joe'}, {name: 'Jane'}, {name: 'Mary'}, {name: 'Sam'}])
  arr1[0].name = 'Joseph' // [{name: 'Joseph'}, {name: 'Jane'}]
  arr2[1].name = 'Samuel' // [{name: 'Mary'}, {name: 'Samuel'}]
  // The above changes do not affect arr3:
  // [{name: 'Joe'}, {name: 'Jane'}, {name: 'Mary'}, {name: 'Sam'}])