A nifty zero-dependency utility for deeply cloning javascript objects and arrays.
NOTE:
Only enumerable properties are cloned. Non-enumerable properties and Prototype chains are not cloned. If used with other data types, it simply returns the arguement passed.
Where immutability matters, javascript fails the developer miserably. Although javascript provides some functional programming features, it manipulates complex data types by mutation. For example
const a = { a: 1, b: 2, c: { d: 4 } }
const b = a;
a[b] = 3;
console.log(a) // { a: 1, b: 3, c: { d: 4 } }
With Object.assign, we can get around this but it only takes us so far since it only performs a shallow copy while nested objects and arrays are still copied by reference.
const a = { a: 1, b: 2, c: { d: 4 } }
const b = Object.assign({}, a);
console.log(b) // { a: 1, b: 3, c: { d: 4 } }
a.a = 2 // no effect on b;
console.log(b) // { a: 1, b: 3, c: { d: 4 } }
a.c.d = 44; // changes b as well
console.log(b) // { a: 1, b: 3, c: { d: 44 } }
This is what deepClone helps to solve.
const deepClone = require('deepClonejs');
let a = let a = {
a: 1,
b: 2,
c: [1, 2, 3, {
e: 5,
f: [{
g: 1
},
{
h: 8
}],
i: 9}
],
j: 10
}
let b = deepClone(a);
a.c.f.g = 500
b.c.f.g = 1 // unaffected by change in a's child object's values
This is particularly useful when mutation is not an option e.g in a Redux application.
npm install --save deepclonejs
const deepClone = require('deepclonejs');
then use as in the example above.